Rion sound level meter

1. PROJECT STORY
Can Sound Be Conducted Via Cartilage?
TALES OF RION
Measuring the Sound Insulation
Performance of Building Materials
HISTORY OF TECHNOLOGY
Part 1: Sound Level Meters
FROM OVERSEAS
Vietnam
OUR FAVORITE TOWN, KOKUBUNJI
[Retro-Modern & Green]
EPILOGUE: SCIENCE, SCIENCE!
The Ehrenfest Urn Model:
Fascinating Irreversibility
FROM NOW ON
How Particle Counters Support Our Society
IN THE BACKYARD
In What Way Rion's Innovation Comes into
Vol. 1
2021/5

2. Almost 80 years ago in 1940,
a group led by businessman Mr. Uneo Kobayashi
founded the Kobayasi Institute of Physical Research,
an organization aimed at research on fundamental and applied physics.
The institute eventually narrowed its focus of research to acoustics.
Kobayasi-riken Co., Ltd. was founded in 1944
to commercialize the results of the institute’s research.
This was the root of our company, Rion.
Our world currently faces various social issues,
such as climate change on an unprecedented scale
and epidemics of infectious diseases.
What can we do and where should we focus our efforts in these times of turmoil?
When I contemplate them, I find myself falling back
on the belief held by our founder, Mr. Uneo Kobayashi.
It’s said Mr. Kobayashi had originally aspired to become a Buddhist monk.
He wanted to pray for the peace and well-being of people
and to help those with problems and those in need.
But Mr. Kobayashi eventually came to believe
that the power of science and technology was essential to realizing his aspirations.
His belief culminated in the founding of the Kobayasi Institute of Physical Research.
Decades have passed since then, but Rion’s vision remains steadfast.
Every day, we ask ourselves what the current needs of the people are.
Harnessing the power of science and technology,
the staff of Rion continue listening to the voices of the people
with sincere interest and concern.
We make life better and contribute to building a healthy society.
President & CEO
Kenichi Shimizu
The Spirit
of Rion We want to help people
and support our society.
That’s why we work endlessly
to perfect our technologies.
PROJECT STORY A Documentary of Product Development at Rion
Can Sound Be Conducted Via Cartilage?
—The Road to the Development
of the Cartilage Conduction Hearing Aid—
HISTORY OF TECHNOLOGY Rion’s Technologies Over the Years
Part 1: Sound Level Meters
From Maker of Sound Level Meters
to Leader in Acoustic Measurement
FROM NOW ON The Present and Future of Rion
How Particle Counters Support Our Society
IN THE BACKYARD On the Front Lines of Technology Development
Interview with Kiyokatsu Iwahashi,
Director of Technical Development Center
In What Way Rion’s Innovation Comes into
TALES OF RION See and Hear Tales of Rion Products and Daily Life!
Measuring the Sound Insulation
Performance of Building Materials
FROM OVERSEAS
Rion Across the Sea - Vietnam
RION STAFF SHOW YOU AROUND — OUR FAVORITE TOWN, KOKUBUNJI
Strolls Around Kokubunji
[Retro-Modern & Green]
ACTIVITY
Rion’s [Activity Report]
EPILOGUE: SCIENCE, SCIENCE! Column by Rion’s staff on their obsession with science
Because We’re Science Lovers
001 The Ehrenfest Urn Model:
Fascinating Irreversibility
02
06
10
12
14
16
17
18
20
Copyright © RION All rights reserved.
No portion of this journal may be reprinted or redistributed without prior consent.
Cover Art: “View from the Kokubunji Cliff Line”
At the foot of the cliff are the cherry blossoms that mark the
arrival of spring. In the distance are the snowy outlines of the
Minami Alps. The print depicts the Rion office building located
in Kokubunji, a town that marks a confluence of humans, his-
tory, and a verdant natural setting.
By Yusuke Kitajima (woodblock artist)
Completed the graduate course in block printing at the
Musashino Art University in 2014. He draws on a unique
method that combines the techniques of woodblock printing
and monotyping to create a single unique print, using familiar
everyday items as subjects.
[Publication]
Kenichi Shimizu
[Planning and Production]
RION Technical Journal Editorial Committee
Nobuhisa Okamoto
Kenichi Matsuzaki
Toshiyuki Hasumi
Atsuhiko Nakayama
Kazuhiko Nakamura
Yoshikazu Hagiwara
Kaori Sakata
Motoyoshi Okuno
Tsuyoshi Maeda
Hideto Nishimura
Masumi Ueta
Isamu Kanou
Hiroyasu Yajima
Ryo Takeuchi
Rika Minagaki
Shinichi Yamazaki
[Editing and Interview]
Miguel Utsunomiya
[Art Direction and Design]
Ken Nishinaka (Nishinaka Design Office)
[Date of Publication]
May, 27, 2021
We’ve published RION Technical Journal, vol. 1, as a
source of technical information from Rion.
We will try to create a journal whose pages provide in-
depth and stimulating content, presented in a refresh-
ing style.
Our goal is to tell our readers about Rion’s current capa-
bilities and our future prospects.
The publication of the RION Technical Journal marks the
end of Shake Hands,
our earlier technical journal. Volume 12, published in
December 2020, is the last issue of the Shake Hands.
We’re grateful to all the readers whose avid interest
made the continuing publication of the journal possible.
Vol. 1
2021/5
We want to help people
and support our society.
That’s why we work endlessly
to perfect our technologies.

3. In 2009, in its prototype phase, the cartilage conduction hear-
ing aid used a bimorph-type piezoelectric vibrator. Its output
was low at 1,000 Hz or less. It required a power supply of 3
V or more and consumed over 60 mW. (A typical hearing aid
consumes about 1 mW.) It was therefore concluded that us-
ing this type of transducer was unlikely to lead to the develop-
ment of a marketable product.
Vibrations of a transducer in the cartilage induce vibrations in the cartilage
of the external auditory canal, generating air-conducted sound in the external
auditory canal.
How a cartilage conduction hearing aid conduction sound (in the presence of an external auditory canal) Edited by Professor Hiroshi Hosoi
Can Sound Be Conducted Via Cartilage?
— The Road to the Development
of the Cartilage Conduction Hearing Aid —
PROJECT STORY A Documentary of Product Development at Rion
In 2017, Rion introduced the world’s first* carti-
lage conduction hearing aid, a product that drew
on the newly discovered third auditory pathway.
Let’s see how this hearing aid was developed and
how it’s entering widespread use.
*According to September 2017 company survey
Hiroshi Hosoi, M.D.
President and Chairman of the Board of
Nara Medical University, Director of the
MBT (Medicine-Based Town) Institute. He
discovered the phenomenon of cartilage
conduction hearing and published 16 pa-
pers on the subject. He played a central
role in joint research with Rion on cartilage
conduction and guided the successful de-
velopment of the cartilage conduction hear-
ing aid.
The Unexpected Discovery
of a Completely New Auditory Pathway
It all began with the idea that sound could
be conducted by inducing vibrations in the
cartilage surrounding the ear. Professor
Hiroshi Hosoi of Nara Medical University
discovered cartilage conduction and initi-
ated the productization of the new type of
hearing aid. He says: “Sound is conducted
from the external auditory canal to the ear-
drum, and then to the ossicles. Eventually,
it’s converted into a nerve impulse in the
inner ear that the brain perceives as sound.
The primary medium that conducts sound
is air; sound perceived from the vibration
of air is referred to as air conduction
hearing.
Sound can also be conducted by directly
inducing vibrations in the temporal
bone, which houses the inner ear. This
type of sound perception is called bone
conduction hearing. For quite some time,
air conduction and bone conduction were
believed to be the only pathways for sound
transmission. Then, in 2004, I unexpect-
edly discovered a third auditory pathway,
cartilage conduction.”
While the bone and cartilage inside our
ears resemble each other, they’re completely
different types of tissue. They’re two distinct
components of the ear. It was known for a
long time that sound could be perceived
via vibrations in the bone, but no one
considered the possibility that sound could
be perceived via vibrations in the cartilage.
Then, one day in 2004, Professor Hosoi
made his great discovery.
Mention hearing aid, and most people
picture an in-the-ear (ITE) or behind-the-
ear (BTE) device. Since these hearing aids
transmit sound to the eardrum, they’re
not useful for people whose external audi-
tory canal is occluded—a condition that
prevents the transmission of sound to the
eardrum. Examples include patients suf-
fering from external auditory canal atresia.
Bone conduction hearing aids of the head-
band or implant type are commonly
prescribed for such patients, but these
devices involve a certain level of physical
discomfort. In response, we developed a
cartilage conduction hearing aid, which
uses a small element called a transducer
fitted to the ear in place of a receiver. The
device represents a dramatic step for-
ward. It’s easily and comfortably worn by
patients with occluded external auditory
canals or by those with ear discharge due to
middle ear infection or the like. This was
the world’s first hearing aid to rely on the
phenomenon of cartilage conduction.
“I was placing a transducer against various
parts around the ear and listening to the
sound it made. I noticed something odd.
The sounds I heard when I held the trans-
ducer against bone and against cartilage
differed. The observation wasn’t based on
any theories or predictions, since I had
none at the time. The sounds just seemed
different. This strange discovery prompted
metocarefullypressthetransduceragainst
various parts around the ear. I confirmed
that the sounds I perceived were quite
different. Had I been an expert in bone
conduction, I might have been trapped
by the preconceived notion that the only
auditory pathways are air and bone. I
might not have noted this difference. This
discovery drove my subsequent research to
understand the reason for this difference.”
Professor Hosoi named this sound
Interview and article by Editorial Committee
Photo by Yuki Akaba
Transducer
2
In developing the transducer
structure, Iwakura would or-
ganize his thoughts by writ-
ing down issues and ideas
in his notebook almost every
day. These small steps even-
tually led to the development
of an innovative structure.
Takashi Iwakura
Advisor of the Technical Development Cent-
er. Ever since joining Rion, he’s dedicated
himself to the development of BA-type re-
ceivers that use magnets and other prod-
ucts. His success in the development of the
core technology, the BA-S-type transducer,
played a key role in the successful commer-
cialization of cartilage conduction hearing
aids.
conduction via cartilage “cartilage
conduction.”
The Road to Developing a Hearing Aid
Based on Cartilage Conduction
Professor Hosoi believes that the sound
conducted by cartilage must have been
heard by researchers throughout all ages
and countries, but that they had simply
overlooked it, chalking it up to bone con-
duction sound. After studying cartilage
vibration in detail, Professor Hosoi found
mounting proof that his intuition had been
correct.
“Bone conduction is the pathway of sound
transmission via vibration of the bone.
So, bone vibration is a prerequisite for
this pathway. Unlike bone conduction,
the mechanism of cartilage conduction
doesn’t necessarily require bone vibration.
The outer half of the external auditory
canal consists of a tube made of cartilage;
the inner half consists of a tube made of
bone. When you hold a transducer against
the cartilage to induce vibrations, the tube
of cartilage vibrates, generating sound
inside the cartilage portion of the external
auditory canal—in other words, inside the
ear. This is similar to how, in a speaker, the
cone vibrates and creates a compressional
wave of air to generate sound. The cylin-
drical cartilage portion of the external
auditory canal serves as the cone. We did
various experiments on auditory percep-
tion and confirmed cartilage conduction
sound had properties distinct from air
conduction and bone conduction sound.”
Ever since his discovery of the auditory
pathway called cartilage conduction,
which had been completely overlooked to
date, Professor Hosoi published a string
of papers on the subject together with the
other scientists on his research team. He
was convinced cartilage conduction would
lead to the development of a new type of
hearing aid.
“The phenomenon of sound being trans-
mittedviacartilageisequivalenttocreating
a sound source inside the ear. This means
we can make a hearing aid or an acoustic
instrument that allows the person wearing
the instrument to hear a sound, but not the
person standing next to him. In terms of
hearing aids, we can generate sound just
by placing the transducer in contact with
the cartilage, without physical discomfort
for the wearer. Bone conduction hearing
aids have to be pressed firmly against the
bone at the point of the bone conduction
transducer. Lots of patients experience
pain when they wear them. A cartilage
conduction hearing aid can even be used
by those suffering from an occluded exter-
nal auditory canal from any cause, simply
by placing the transducer in contact with
the cartilage. As an otolaryngologist, I’d
wanted to provide a comfortable hearing
experience to as many patients as possible.
But for several years after my discovery, I
couldn’t get my papers published in any
of the prestigious international journals—
mostly, I think, because my peer reviewers
were unfamiliar with the newly discovered
phenomenon of cartilage conduction and
because the literature had no previous
research on the phenomenon. So my refer-
ence sections were nearly empty. Then one
day, a chief editor of a medical journal was
visiting Japan and I had the opportunity
to demonstrate the cartilage conduction
instrument to him in person. His reaction
to experiencing cartilage conduction of
sound was a very surprised ‘Oh!’ I got his
attention. A paper I submitted soon after
was accepted and published. Through
these efforts and by enlightening others, I
managed to win increasing recognition for
the phenomenon of cartilage conduction.”
In 2010, the joint research with Rion began
to develop a hearing aid based on cartilage
conduction. At Rion, the search was on
to find ways to effectively apply this new
auditory pathway to hearing aids.
One Roadblock after Another
Takashi Iwakura serves as an advisor at
Rion’s Technical Development Center. He’s
one of the engineers who took on the chal-
lenge of developing a cartilage conduction
hearing aid. Quite early, he came across a
seemingly insurmountable obstacle and
concluded a commercial product wasn’t
feasible. Iwakura explains his conclusion.
“We were told piezoelectric transducers
provided good hearing performance, so
we started making prototypes. But they
needed a power supply of at least 3 V for
Cartilage Conduction Hearing Aid
An ordinary hearing aid is worn by inserting a receiver into
the ear. In contrast, with a cartilage conduction hearing aid,
a part called a transducer is attached to the cartilage at the
entrance of the external auditory canal. Amplified sound is
transmitted to the cartilage. As with ordinary hearing aids,
cartilage conduction hearing aids run on a single button cell
battery. Currently, they can be purchased following consul-
tations at any of 102 designated medical facilities around
Japan.
Scan this for product inquiries.
3

4. the IC to drive the transducer. (Typical
hearing aids run on a 1.4 V zinc-air button
cell.) Even worse, IC power consumption
exceeded 60 mW—more than 60 times the
power consumption of an ordinary hear-
ing aid. And the amplitude of the sound
generated by the piezoelectric transducers
in the low-frequency range was small, that
is, the output was insufficient. This led me
to conclude fairly early that development
of a commercial product using piezoelec-
tric transducers wasn’t feasible.”
Thus, early in his efforts, Iwakura was
forced to embrace a paradigm shift. He
looked for ways other than the piezoelec-
tric method to drive the transducer. At
this point, he tapped into his experience
in developing balanced armature type
(BA type/electromagnetic drive method)
receiversimmediatelyafterjoining Rionand
decided to proceed using an electromag-
netic transducer. He received a grant from
NICT (National Institute of Information
and Communications Technology) to
develop this electromagnetic transducer,
giving him a fresh start. But things didn’t
proceed smoothly.
“I created a transducer prototype with an
electromagnetic structure and achieved
higher output than the piezoelectric trans-
ducer. But the electromagnetic transducer
was extremely delicate, vulnerable to
impact. It wouldn’t have withstood real-
world use. Simply dropping it would affect
the magnetic armature. So—another major
obstacle.”
Curiously,Iwakurasays,heneverconsidered
giving up. His retirement in 2011, nearly
two years after the request to create a pro-
totype, worked to his advantage. Released
from his managerial responsibilities, he
found himself in an environment and mind-
set that allowed him to devote his time and
efforts to his project. The company wasn’t
prepared to mobilize major resources for
the project at this point. Iwakura spent
his days by himself, working through trial
and error. To his colleagues, he may have
appeared to be fighting a solitary battle
with no finish line in sight.
Piece Together Correct Logic
So That the Goal will Come in Sight
Then came a turning point. Iwakura had
continued creating one prototype after
another and presented them within his
department. One day, in search of a solu-
tion, someone provided a major clue.
“Dr. Munehiro Date had become an advisor
at Rion after his retirement from RIKEN.
He’d often provided advice. Once, he sug-
gested I should provide air gaps on not
one but both sides of the armature. That
was the biggest hint. A little while back, I’d
patented a structure resembling what he’d
suggested, although the movement wasn’t
the same. But I had a feeling this was a
breakthrough. The hint led to finding the
correctsequenceoflogicfor creating a novel
structure for the BA-S-type transducer.”
Another name for the term armature is
“movable iron piece.” In a conventional
BA-type structure, the armature is placed
between two magnets with air gaps in
between.It’sacantileverstructure,withthe
armature fixed to the yoke. In this case, the
armature has to be magnetic. It’s produced
by annealing inside a high temperature,
hydrogen atmosphere furnace to achieve
its magnetic properties, so the armature
ends up having lower spring character-
istics than common spring materials. In
contrast, the new BA-S structure uses four
magnets to create BA structures on both
the right and left sides. A flat plate-shaped
armature is positioned between them, with
sufficient air gaps secured. Four springs
are placed between the armature and the
yoke. The springs provide the force that
returns the displaced armature. This novel
structure dramatically improved impact
resistance and made it possible to make
a transducer with much more freedom
in design, one that could be made to any
dimensions.
“I was quite impressed with the resulting
prototype. That was in 2013. At that point,
Bone conduction hearing aids are worn using a
headband and must be held tightly in place, cre-
ating significant physical discomfort.
First, a mold of the ear shape is taken, followed
by a 3D scan, to perform 3D modeling of an ear
chip on the computer. The ear chips are ulti-
mately made to fit individual ear shapes using a
3D printer. This manufacturing process was de-
veloped through joint efforts between Watanuki
and the production department.
The actual BA-S type electromechanical converter adopted
for the cartilage conduction hearing aid is this size.
This is the new structure of the
electromechanical converter devel-
oped for the cartilage conduction
hearing aid (conventional type to
the left, new BA-S type structure
to the right). The most notable fea-
ture of the new structure is the ad-
equate air gaps at both right and
left ends of the armature. The mode
of vibration for the new structure is
translational.
Conventional type
Comparison of electromagnetic structures
for conventional BA type and new type
(schematic illustration)
Examples of actual structures
(mode of vibration: pendulum for conventional type and translational for new type)
Yoke
The new structure (BA-S)
Armature
Magnet
Coil
Spring
Direction of magnetization
Keisuke Watanuki
EngineeringManagerofGroup1,Component
Technology Development Department,
Technical Development Center. He spent
many years designing hearing aid hous-
ings, applying his knowledge of mechani-
cal engineering. In developing the cartilage
conduction hearing aid, he dedicated him-
self to designing a special device for testing
hearing aid characteristics.
4
I even thought this would become the stan-
dard design for transducers in the future.”
At Rion, this structure is now referred to
as the “i transducer.” The “i” of course is
the first letter of Iwakura’s family name.
He reflects on how he managed to realize
this structure.
“The road was pretty rough, but I felt it
ultimately depended on how the logic
could be pieced together. I didn’t have the
goal clearly in my sights yet, but I learned
from my mistakes and listened to advice.
I felt I was making progress, even if it was
very slow progress. I am a later bloomer.”
In 2013, the development of the cartilage
conduction hearing aid was adopted as a
commissioned project by the Ministry of
Economy, Trade and Industry. Those of
us at Rion got to work for three years in
partnership with Nara Medical University
(in charge of clinical evaluations) and the
Chofu Electronics Engineering Co., Ltd.
(in charge of mold production for the
transducer parts). By that time, we had the
manpower, the materials, and the funds to
develop a real product.”
In Search of an Ear Chip
to Fit Any Ear Shape
In 2013, Keisuke Watanuki joined the
team to develop the cartilage conduction
hearing aid. He took a course that differed
from the course taken by Iwakura in the
latter’s efforts to develop a transducer and
found himself struggling to find his way
in the dark. Watanuki had experience in
designing hearing aid housings. His role
in developing the cartilage conduction
hearing aid was to develop the ear chip
(attachment part) for attaching the hearing
aid to the ear.
“When I first laid eyes on the cartilage
conduction hearing aid being developed
with its large battery, I honestly had doubts
it would ever become a product. But over
time, working alongside Iwakura, I began
to believe it would become a great product.
My excitement kept growing as our goal
came into sight.”
What he found most challenging was
finding a way to fit the ear chip to the ear
shape of potential users. The individual
cases presented by potential users vary
significantly—some may have no external
ear, others may only have a slight surgi-
cally created indentation. In order to fix
the transducer properly onto the ear of any
user, Watanuki had to find a way to make
customized attachment parts.
“The heavier the ear chip, the lower the
sensitivityinthehigh-frequencyrange,soI
had to create a lightweight ear chip design.
Another problem was the alignment of the
direction of the vibration with the direc-
tion of the user’s head. That’s necessary to
maintain sensitivity. That’s why I decided
to proceed with design work applying a
custom-made hearing aid system with 3D
printing technology, something that could
create ear chips of complex shapes.”
He collected molds of various ear shapes
and did 3D scans and modeling before
the 3D printing process. He repeated this
process over and over. It was extremely
challenging to create a lightweight ear chip
that would fit securely while maintaining
the desired direction of vibration.
“For ordinary hearing aids, an ear chip
can be made once you have the ear mold.
But the ear shapes of potential cartilage
conduction hearing aid users are expected
to be much more diverse. I also used
photographs of each individual’s ear to
determine the optimal ear chip shape. If
the finished ear chip is heavy, auditory
quality suffers, and the risk of users drop-
ping the hearing aid grows. So I had to
shave off as much excess weight as possible.
Initially, the person in charge of produc-
tion told me it was impossible. But as we
made more prototypes, we both slowly but
surely gained experience and know-how.
Although, even then, I have to say the goal
still seemed a great way off.”
Eventually, Watanuki succeeded in manu-
alizing the ear chip production procedure
with the cooperation of the person in
charge of production. When asked about
his satisfaction with his achievement, this
was his reply.
“I was present for the validation of the
comfort of the cartilage conduction hear-
ing aid performed at the Nara Medical
University. A little child reluctantly put
on the hearing aid while the mother stood
by looking very worried. When the child’s
face instantly lit up, I knew the child could
hear. The mother began to weep with joy.
I too shed tears in sympathy. I wouldn’t
trade that moment for anything. That
moment was truly a reward.”
Opening a New Door
to Hearing Aids
Yoko Fujishima, one of the frontline staff
at the Rionet Center, offers hearing con-
sultation services to her clients daily and
provides them with optimal solutions. The
emergence of cartilage conduction hearing
aids, she says, has expanded the range of
the solutions she can offer.
“I can’t recommend air conduction
hearing aids to those born without a
properly-formed external auditory canal.
In those cases, I have no choice but to
recommend a bone conduction hearing
aid. The cartilage conduction hearing aid
changed all that. Now I can offer a wider
range of solutions. The transducers on
bone conduction hearing aids had to be
fixed tightly in place with pressure. Many
users find this physically distressing. The
cartilage conduction hearing aid also has
the advantages of being smaller and less
noticeable.”
It took almost 13 years to develop the
cartilage conduction hearing aid after
the discovery of cartilage conduction by
Professor Hosoi. The path wasn’t smooth
and had many hurdles and obstacles.
Growing numbers of medical facilities are
currently prescribing them, and cartilage
conduction hearing aids have found their
way into the lives of many people. A new
door to hearing aids had indeed been
opened.
Manufacturing the transducers, the key component of the
cartilage conduction hearing aid.
Yoko Fujishima
Currently works at the Rionet Center, a cer-
tified shop specializing in hearing aids. She
is a certified hearing aid technician, respon-
sible for the sales and maintenance of hear-
ing aids at the shop or medical facilities. To
date, she has sold and adjusted cartilage
conduction hearing aids to approximately
80 patients at clinics in Tokyo where they
are available.
5

5. HISTORY OF TECHNOLOGY
Sound Level Meters
Rion introduced its first sound level meter during Japan’s post-war recovery when
noise from factories and public transportation systems emerged as a major social
issue. More than half a century has passed since then. Today, to learn about the his-
tory and technological development of portable sound level meters, we’ll interview
Tomoharu Wakabayashi, an engineer who devoted many of his years at Rion to the
development of sound level meters.
From Maker of Sound Level Meters
to Leader in Acoustic Measurement
Part 1:
Interview and article by Kana Yokota
Photo by Yuki Akaba
Rion’sTechnologiesOvertheYears
Tomoharu Wakabayashi
Director of the Innovation Promotion Divi-
sion. He’s been involved in the develop-
ment of sound level meters for more than
20 years since joining Rion in 1986. With
his mindset of always thinking one step
ahead of trends in measurement technolo-
gies, his role in designing circuits offering
both high precision and low power con-
sumption, and in promoting the transition
from analog to digital instruments has been
pivotal in Rion’s history of sound level meter
development.
6
Initiating Development of Sound Level Meters
in Response to the Growing Problem of Noise Pollution
Seven typical pollution problems that pose issues for the national, as well
as municipal governments, are air pollution, water pollution, soil contam-
ination, noise, vibration, land subsidence, and offensive odors. Of these,
noise is the most serious in terms of the number of complaints received
and the levels of sensory and psychological stress involved. The number
ofcomplaintsreceivedconcerningnoisehasremainedmostlyconstantor
risen over the past 20 years.
In Japan, Rion introduced its first sound level meter in 1955. This was
during the post-war recovery, a time when noise from factories, construc-
tion sites, and public transportation systems was emerging as a major
social issue, mainly in urban areas.
“Outside Japan, New York City was already facing the problem of noise
generated by construction work, cars, and elevated railways in the 1920s.
By 1930, people were taking noise measurements. In 1953, Koji Sato, one
of the founders of the Kobayasi Institute of Physical Research (Rion’s pre-
decessor) and our fourth president and CEO, attended the 1st Interna-
tional Congress on Acoustics as a representative of Japan. During his trip,
he acquired a sound level meter in the United States to launch a develop-
ment project, and that was the start of the sound level meter business at
Rion.”
At that time, Rion had been producing sensors for microphones and ear-
phonesaswellashearingaidsandotheracousticproducts.Thetechnolo-
giesfortheseproductsandtheresultsofresearchattheKobayasiInstitute
ofPhysicalResearchwereappliedtocreatetheN-1101,anindicatingsound
level meter, which offered a measurement range of 45–130 phons. The
model was received well and entered wide use in noise countermeasures
and occupational health measures by cities and researchers in noise-re-
lated fields. Since then, Rion has worked with governmental agencies like
theEnvironmentalPollutionResearchInstituteoftheTokyoMetropolitan
Government and the Kobayasi Institute of Physical Research to develop
and provide more sophisticated sound measuring instruments.
As Japan entered its period of rapid economic growth in the 1960s, this
led to further aggravation of the problem of environmental pollution
throughout the country, which in turn led to the promulgation of the
Basic Act for Environmental Pollution Control in 1967, the Noise Regula-
tion Act in 1968, and JIS C 1502 in 1970. These regulations dramatically
increased the demand for sound level meters among municipalities and
businesses.
Initially, Rion was required only to obtain permits to manufacture sound
level meters, specified as measuring instruments in the Measurement
Act. Then, as a result of government inspections becoming mandatory
in 1973, Rion’s NA-09 became the first sound level meter in Japan to win
government approval. The popularity of this model grew explosively for
use in measuring noise pollution, which had become even more serious.
Around that time, needs began to emerge for recording and analyzing
functions that would help in devising practical noise countermeasures, to
which Rion responded with various technological innovations.
In the 1970s, the pollution problem was at its peak, and related measure-
ments were being made throughout Japan. Rion’s street noise digital dis-
play system helped raise public awareness of noise regulations. The first
units were placed in front of Shibuya Station and at a Nishi Ginza inter-
section in Tokyo. We changed the public perception of the problem by
allowing people to view noise levels on a large digital display board.
From Maker of Sound Level Meters
to Maker of Acoustic Measuring Instruments
In 1978, Rion produced the NA-20 sound level meter. In addition to the
requirements oftheJISandtheMeasurementAct,thismetthestandards
ofinternationalIECstandards.Thismodelbecamethebasemodelforthe
development of future sound level meters.
At the time, Rion had established itself as a manufacturer of sound level
meters. But it was yet to provide precision systems that would elevate
[N-1101] (1955)
The N-1101 was Rion’s first
sound level meter and the first
compact sound level meter
made in Japan. The measure-
ment range was 45–130 phons.
The model was widely used in
noise countermeasures by city
governments and in occupa-
tional health measures.
[NA-07] (1964)
The NA-07 was a portable in-
dicating sound level meter.
Cutting-edge designs were
adopted for the microphone
attachment, the calibration de-
vice, and the handle. The out-
put terminal was isolated from
the circuitry for the sound level
measurement, allowing users to
perform analysis and recording
while viewing the meter.
[NA-09] (1974)
This model became the first in
Japan to receive S-1 type approv-
al as an ordinary sound level me-
ter. Equipped with a condenser
microphone, the popularity of
the NA-09 grew explosively as an
instrument for measuring noise
pollution which had become an
increasingly pressing problem.
[NA-20] (1978)
Development of the NA-20 was
based on painstaking attention
to detail. It took three years,
from conception to release of the
product. The model met interna-
tional IEC standards, in addition
to the requirements of the JIS
and the Measurement Act.
Interview and article by Kana Yokota
Photo by Yuki Akaba
7

6. [LR-06] (1992)
The LR-06 was a servo recorder
with wide-ranging applications,
from level recording of noise
and vibration to characteristics
measurement of various acous-
tic instruments, and even linear
recording of electric voltages.
Compared to conventional level
recorders, the LR-06 incorporat-
ed digital technologies to offer
numerous functions.
[NL-04] (1991)
The NL-04, a key model in the
history of Rion sound level me-
ters, could be connected to the
memory card unit of the DA-05,
developed at the same time to
make digital recordings of sound
levels for extended periods.
[NL-06] (1997)
The NL-06 was an integrating
ordinary sound level meter
equipped with a display having
a linearity range of 100 dB and
a memory card slot. The model
was developed to respond to the
need for continuous measure-
ments of equivalent continuous
sound pressure levels follow-
ing the enactment of the Basic
Environment Act.
[NL-18] (1995)
A precision integrating ordi-
nary sound level meter, the NL-
18 was a high-performance
multi-function model with two
internalized circuits for sound
level measurements that allow
users to measure sound pres-
sure peak values or take mea-
surements using impulse time
constant, in addition to measur-
ing equivalent continuous sound
pressure levels. It featured two
liquid-crystal displays.
its status as a manufacturer of acoustic measuring instruments. Thus,
Rionkick-startedseveraldevelopmentprojectsthatwouldbridgethegap
between being a maker of sound level meters and becoming a maker of
acoustic measuring instruments.
Development of the NA-20 included the following innovations: a poly-
mer film microphone; a meter-type indicator offering a wide range, high-
speed, and precision performance; a precision effective value detection
circuit;andahousingwithsuperioracousticperformance.Acadreofelite
engineers pushed all core components of the sound level meter to the
next stage.
The period of rapid economic growth for Japan lasted until the burst
of the bubble economy in the early 1990s. Around this time, industrial
growth also came to a screeching halt. As the growth of acoustic and
vibration measuring instrument businesses slowed, in response to the
diversificationofmeasuringapplications,suchasformonitoring,diagnos-
ing, and prevention, demand for more advanced measuring instruments
grew. The LR-06 was a level recorder that answered these needs.
“Level recorders can capture temporal changes in noise on recording
paper. They allow the user to determine the environmental impact of
certain sounds at a given site. For example, measurements of road traf-
fic noise can be affected by a cawing crow or a passing ambulance. The
magnitudeoftheimpactofsucheventsonameasurementdependsboth
on their sound level and how often they occur. Therefore, the user may
note on the recording paper a crow cawed at a particular point so that
thecorrespondingdatacanberemovedfromtheanalysis.Theprocedure
is pretty analog, but since conditions in the field were liable to change
by the minute, making recordings on paper proved quite convenient. In
any case, the people working in the field in those days preferred data on
paper. The LR-06 also featured digital technologies that allowed simulta-
neousdatarecordingonamemorycardinparallelwithanalogrecording
and automatic time printing.”
Another key model in the history of sound level meter development at
Rion was the NL-04 ordinary sound level meter. Users could make digital
recordings of sound levels over an extended period simply by connecting
ittotheDA-05memorycardunitdevelopedatthesametime.Thismodel
paved a new road to post-measurement data processing.
“Levelrecorderswerelargeandboxyandoftencumbersometocarryinto
the field with the sound level meter. The data recorded on the memory
card of the DA-05 could be played back later to create a hard copy using
theLR-06,whichwasdevelopedatthesametime.Thiswasaninnovation
that made measurement activities in the field less laborious.”
Both the NL-04 and LR-06 won high acclaim for their functions as
advanced measuring systems, winning the Good Design Award in 1991
and the 1st Technical Development Award by the Acoustical Society of
Japan in 1993.
“For each new model, I always think about what new feature I can real-
ize—abouthowtostayonestepaheadwithinthecurrentstateoftheart.”
With amendments of the Environmental Quality Standards for Noise in
1998, the drafting of JIS Z 8731 in 1999, which stipulates procedures for
describing and measuring noise, and amendments of the Noise Regula-
tion Act in 2000, the equivalent continuous A-weighted sound pressure
level (LAeq) became the index for noise evaluation.
“The change of the index for noise evaluation was a major turning point
in sound level measurement. Evaluating equivalent continuous sound
pressure levels requires continuous measurements over extended peri-
ods. This expanded demand for automated measurement systems. Shift-
ing market trends always present opportunities for technological leaps.
In this case, they led to a major transition in our measuring instruments:
extendedrecordingsmadepossiblebyproprietarydatacompressionand
extraction technologies and convenient data processing using personal
computers.”
A new series of sound level meters followed.
“The NL-21 series, released in 2001 to become a frontrunner in the global
market, was an epochal product imbued with the ambition of our devel-
opers to produce a next-generation sound level meter for the 21st cen-
tury. The five models in the series, from the flagship model to the base
model, shared a common platform. Users could add various functions
8
RDD1125
The Easter Egg in the Model Number
Rion’sproductsrepresentthefruitofhardworkbytheirdevelopers.It’salittle-known
fact that the model number for the RDD1125 power supply module, designed as a
special component for the NL-04, the development of which Wakabayashi contrib-
uted to, contains the date of his son’s birthday. This is hardly household knowledge.
But it signals that all products are special to developers, just as their children are.
[NL-42A] (2020)
The latest handheld sound level
meter, the NL-42A, offers vari-
ous optional programs and soft-
ware, allowing users to perform
measurements as desired. It’s an
eco-friendly model compatible
with rechargeable batteries. The
NL-62, another model in the se-
ries, performs measurements at
ultralow frequencies of around
1 Hz.
[NL-42] (2011)
Designed to provide improved
measurement reliability, the
handheldNL-42soundlevelmeter
marked a full model change from
the preceding model. It featured
high waterproof performance,
in addition to high precision and
high stability made possible by
extensiveuseofdigitalprocessing
technologies. The model had
enhanced user-friendliness with
a color LCD touch panel that can
display multiple languages.
[NL-27](2009)
The NL-27 is a compact, light-
weight, wide-range sound level
meter. It offers remarkable sim-
plicity and usability for measure-
ments of equivalent continuous
A-weighted sound pressure lev-
els, maximum sound levels, and
sound exposure levels.
[NL-21](2001)
TheNL-21offeredalinearity range
of 100 dB to eliminate the need
to switch level ranges. The mod-
el made simultaneous measure-
ments of equivalent continuous
A-weighted sound pressure lev-
els, percentile noise levels, and
maximum sound levels and of-
fered various extended functions
to allow a wide range of noise
measurements.
like frequency analysis to the sound level meter using a memory card
containing the program required to implement the extended function.
The product also offered a sound recording function for evaluating data
validity.”
The NL-21 series received the 10th Technical Development Award from
theAcousticalSocietyofJapanforcontributionstonext-generationnoise
evaluations.
For a Future in Which People Can Live in Comfort
In the 2000s, as technologies began to advance rapidly in various fields,
Rion continued to produce sound level meters that met measurement
needs—theultra-compactNL-27,whichoffersawidemeasurementrange
but can fit into one’s pocket; the NL-42, the first device made in Japan to
adopt a waterproof construction; and the NL-62 developed in 2012, so
advanced that a single unit is capable of simultaneous measurements of
ultralow frequency sound and environmental noise.
“Every new product represents the total commitment of the developer,
with limitless support and contributions from those around,” comments
Wakabayashi.
“There’s this basic component called a condenser. I once collected every
condenserIcouldgetmyhandson.Itestedeveryoneofthemandcreated
a part offering the performance we needed by carefully selecting and
combining them. Our procurement department is especially resourceful.
OnceIconsultedwiththemontherequirementsforanLCDthatIneeded
for the next product, and in response, they scoured Japan for a manufac-
turer who could produce custom-made LCDs.”
Sound level meters are valuable equipment for their users. Once pur-
chased,mostcanbeexpectedtoremaininserviceformorethan10years,
meaning quality and durability are always requisite in their development.
Throughdiligentinspections,calibration,andrepairs,someusersmanage
to keep using the same unit for more than 20 years.
It’s been 66 years since the development of our first sound level meter.
Awareness of noise has grown and significant improvements have been
made to resolve noise pollution problems. Still, Wakabayashi believes the
problem of noise will most likely persist.
“Automobile engines are quieter, and the adoption of low-noise pave-
ments reduces the sound of the automobiles moving over them. But that
doesn’t mean we’ll be noise-free. When the acoustic insulation perfor-
manceofabuildingimprovesandaroombecomesquieter,peoplebegin
to notice the noise from the air conditioning system or the refrigerator.
And when these sounds become quieter, then more subtle sounds jump
out. That’s human nature. At Rion, we’ve been developing sound level
metersandlookingatmeasurementasawaytocreatebettersoundenvi-
ronments. We’ll continue to search for things we can do to provide the
best solutions to familiar issues regarding sound.”
Making lives more comfortable means creating more comfortable envi-
ronments, for which measurement is fundamental. In the future, sound
level data collected by IoT will make it possible to monitor and map every
kind of noise encountered in the world. Rion’s role is to realize comfort-
ablesoundenvironmentsbymakingprecisionmeasurementwidelyavail-
able. Make products a step ahead of the times. The never-ending effort,
inquiring minds, and passion of our predecessors are legacies passed
down to our current engineers at Rion. As a frontrunner in acoustic mea-
surement, Rion is dedicated to continuing to move forward.
9

7. From pharmaceuticals to semiconductors, Rion’s particle counters are at work behind
the scenes in a broad range of industries.
Following the development of airborne and liquid-borne particle counters, in recent years,
Rion has developed and introduced viable particle counters.
Here we’ll introduce the current and future state of evolving particle counting technologies.
Light Scattering Airborne Particle Counter
KC-22B (2001)
The KC-22B determines particle number concen-
trations by measuring the diameter and number
of particles suspended in air by the light scatter-
ing method. It’s lightweight and compact, offers
high output and long service life, and incorporates
a high stability optical system. To achieve superi-
or durability, it incorporates a semiconductor la-
ser-pumped solid-state laser as its light source.
Rion’s Particle Counter
Widely Deployed in Various Fields
An airborne particle counter counts the
number of particles suspended in air by
observing the light scattered by particles.
The technology was developed to pro-
tect workers from radioactive particles
suspended in air during the production
of nuclear bombs in World War II. In 1973,
Rion became one of the first companies to
introduce this technology to Japan.
Initially, particle counters made in the US
were imported as instruments for mea-
suring air pollution and addressing indoor
environmental health problems. But some
of these products created dissatisfaction
among users in terms of quality and main-
tenance. In response, in 1977, Rion devel-
oped and marketed the KC-01, the first par-
ticle counter made in-house by a Japanese
company.
The KC-01 featured a minimum measur-
able particle diameter of 0.3 μm, first-rate
performance for counters at the time. It
cost less than 1 million yen. This made the
counter very popular. It saw sales growth
mainly in the market for contamination
control of drug companies’ cleanrooms.
The largest user was the semiconductor
industry, at that time on the verge of rapid
growth. At semiconductor manufacturing
sites, contamination of silicon wafers by
airborne particles can significantly reduce
yieldratios.Contaminationcontrolbyparti-
cle counters was essential to secure quality
and profit margins.
In 1984, Rion developed the first domes-
tic liquid-borne particle counter. Product
development was in response to growing
demand from the pharmaceutical industry
for instruments capable of counting parti-
cles in parenteral solutions for injections or
other liquids.
“Rion’s liquid-borne particle counter is
also used in the Super-Kamiokande giant
neutrino observation facility, set 1,000 m
below ground in Kamiokacho, Hida City, in
Gifu Prefecture. This was picked up by the
media,whichhelpedRion’sadvancedtech-
nologies gain wider general recognition.”
Foreign companies are also big customers.
In particular, Rion’s measuring instruments,
which have helped maintain the compet-
itiveness of Japanese companies, have
received high acclaim in the semiconduc-
tor industry in the Asia region. Its airborne
particle counters were also used in Japan’s
Kibo experimental module of the Interna-
tional Space Station.
Precision, Durability, and
—a New Arrow in Our Quiver—
Minimum Measurable Particle Diameter
In2007,aroundthetimeoftheintroduction
of the iPhone by Apple Inc. of the US, per-
sonalcomputers,smartphones,andtablets
had already started flooding the market.
This rise in consumption encouraged Japa-
nese semiconductor manufacturers to shift
production centers overseas. In the 1990s,
Rion began strengthening sales activities
to Japanese-affiliated companies in semi-
conductor fields who had moved abroad.
But the demands from all these companies
werethesame,regardlessoflocation.Allof
them wanted just one thing: the ability to
reliably count ever smaller and smaller par-
ticles than before.
“Particle counters all work on the same
basic principles. So our competitors flocked
to join the global race in pursuit of the
smallestpossiblemeasurableparticlediam-
eter. While we lagged behind in the race a
bit from time to time, we adopted a strat-
egy of focusing on measurement precision
in developing our particle counters.”
In 2009, Rion marketed the KL-30A liq-
uid-borne particle counter for pure water,
anintegratedunitcombiningasensor,con-
troller,andflowmeter.Thedevicemonitors
particles in ultrapure water to a minimum
measurable particle diameter of 0.05 μm.
Applying the technology for this model,
Rion developed the KS-18F light-scattering
liquid-borne particle counter, which uses a
sapphire cell to detect particles of 0.05 μm
in diameter in chemical solutions, mainly of
hydrofluoric acid. In 2013, Rion succeeded
in developing the KS-19F light-scattering
liquid-borne particle counter. This device
detects particles to a minimum measurable
Interview and article by Kana Yokota
How Particle Counters Support Our Society
》 》
FROM NOW ON
The Present and Future of Rion
Takashi Minakami
Technical Development Center. In addition
to working on the development of particle
counters, he’s also involved in joint research
with the National Institute of Advanced
Industrial Science and Technology (AIST) on
calibration technologies for airborne parti-
cle counters.
10
Reflection
Wavelength, refractive index of particle,
and refractive index of medium are constant
Intensity of scattered light
is dependent on particle diameter
Particle Refraction
Light
Absorption
Diffraction
Viable Particle Counter
XL-10B (2011)
Rion developed the XL-10B viable particle counter
by applying technologies acquired in the develop-
ment and production of particle counters. Viable
particles are irradiated with a violet laser of a spe-
cific wavelength to induce autofluorescence by a
certain substance inside the cell. This fluorescence
is detected to make real-time measurements of the
number and size of the viable particles. The process
requires no preprocessing of the samples, such as
dyeing or cell culturing.
particle diameter of 0.03 μm, a world-lead-
ing achievement at the time.
“We developed these models by bringing
together all of Rion’s technologies. Rion’s
strengths lie in precision and durability,
qualitiesthatmakeourinstrumentsreliable
and trouble-free. It’s an approach we’ve
cultivated throughout our long history.”
Continuing to Develop Particle Counters
in Response to the Needs of the Times
Rion has won trust both in Japan and
abroad for its dedication to the devel-
opment of precision particle counters. In
2011, it introduced the world’s first viable
particle counter (picoplankton counter TM
)
to the market. This device is capable of dis-
tinguishing viable particles from nonviable
particles in water and can make real-time
measurements of viable particles like bac-
teriaandplankton.Themechanismofmea-
surement relies on a biological substance
present inside viable particles that exhibits
autofluorescence. Upon irradiation with a
violetlaser,thisinducesautofluorescencein
the particles, and the fluorescence emitted
is detected using a fluorescence meter. The
counter can instantaneously determine
whether the particles being counted are
viable or nonviable.
“Themostimportantprocessatsiteswhere
foodstuffs, drinking water, and water for
medical and pharmaceutical uses are han-
dled is confirming freedom from contam-
ination by foreign materials like bacteria.
Despite requirements for thorough sani-
tary and contamination control, conven-
tionalmonitoringwasmainlyimplemented
by measurements based on the cell culti-
vation method. Confirming the presence
of bacteria by cell cultivation takes three
to five days, during which the plant has to
be shuttered. In contrast, a viable particle
counter can instantly determine the pres-
ence of bacteria, fungi, and yeasts sim-
ply by passing the water to be managed
through the instrument. Real-time water
quality monitoring significantly reduces
the cost and labor associated with the task.
We anticipate growing demand for these
instruments.”
Since 2020 and the Covid-19 pandemic,
demandfordetectingviruses,bacteria,and
other airborne organisms has increased.
“Viruses and bacteria don’t become air-
borne on their own—they have to ride on
other kinds of particles. We see increasing
demand for counting microplastics, some-
thing being recognized as a serious issue.
We’re currently developing particle count-
ers to respond to all these needs.”
Even now, the particle counter team is test-
ing new approaches as part of vigorous
and persistent efforts to develop sensors
and detection technologies that will push
the limits of minimum measurable particle
diameter and respond to the needs of the
times.
What are particles?
Particles (fine particles) are defined as matter of
sub-micron size (less than 1 µm or so in diame-
ter) that remain suspended in air or liquid with-
out settling. Different fields use different methods
to measure such particles. To manage building air
conditioning systems or when measuring PM2.5,
particles are monitored by measuring their weight
in a given quantity of air. In environments like semi-
conductor cleanrooms, hospital operating rooms,
or spaces in which pharmaceuticals are manufac-
tured, particles are monitored by size and count.
Suspended particles in cleanrooms are counted
by the light scattering method; cleanliness is rep-
resented by the size of the particles determined
from the amount of scattered light (light-scattering
equivalent diameter).
Interaction between light and particles
Once particles become smaller than the wavelength
of light, the scattering of light energy by the par-
ticles becomes dominant over reflected or diffract-
ed light. The intensity of the scattered light exhibits
a specific correlation to the particle size, the re-
fractive indices of particles and medium, and the
wavelength of light. Thus, the particle size can be
determined by measuring the amount of scattered
light.
Particles in the atmosphere
0.0001 0.001 0.01 0.1 1.0 10 100 1,000 10,000
Tobacco smoke
Some examples
of particles
Cement
Pigment Hair
Soot Spore Dust from heavy industry
Silica sand Pollen
Virus
Microbe
Bacterium Fungus
Alga
ZnO, MgO
Chemical
substance Gas molecule
Ultrafine particles
Fine particles
Particle diameter［µm］
Coarse particles
11

8. “Chemical Reactions” at the Center
Drive Technology Innovations
—Can I start by asking about the role played by the TDC as a
driving force behind Rion’s amazing breakthroughs?
We coordinate the efforts of divisions of three product types -
medical instruments, environmental instruments, and particle
counters—to promote basic research and find solutions. Nearly
80% of our activities involve renewing or updating current prod-
ucts. We identify various issues—for example, what functions or
settings need to be added or modified to keep pace with society’s
changing needs—and seek solutions. The remaining 20% or so
involves research for predicting demand for products and services
and developing products and technologies from scratch that will
support society in the future.
—As the director of the center, what do you demand from your
staff in terms of their activities?
I know all our staff have their own diverse ideas. My hope is that
they proactively present these ideas to others, rather than keeping
them to themselves. I believe exchanging ideas, both within and
outside the company, has the power to catalyze unexpected chem-
ical reactions. Exciting project plans can grow out of combining
ideasthatpreviouslyamountedonlytospeculationatthelevelofan
individual. I also want our staff to take the lead in various activities
outside our company. Engineers tend to narrow their focus to the
issues right before them. But making a conscious effort to be more
active outside the company is important for expanding the scope
of their interests. That’s one of the reasons behind the founding
of the TDC. Here, engineers affiliated with different sections meet
and engage each other. They learn what themes other engineers are
working on. How will their inquisitive minds react to themes in
fields they aren’t acquainted with? How can they incorporate that
newly acquired knowledge into their own themes? That’s what’s
truly of value.
—Could you share with us some specific examples of “chemical
reactions” catalyzed through idea sharing?
Let’s see... You could compare Rion’s particle counting technology
to counting stars in the nighttime sky. You can’t see the stars
during the day because of the sun. But say someone needs to count
the stars during the day. One of the staff asked if anyone knew the
solutions. In response, someone from the hearing aid development
team proposed a totally unexpected mathematical solution.
Hearing aids amplify sound to assist hearing. The key idea involves
picking out the voice of the person the user is talking to against a
background of noise. That’s where the solution for detecting stars
came from—technology associated with hearing aids. Lowering
the boundaries between fields by exchanging ideas—I could name
many other cases where this resulted in breakthroughs at the TDC.
On the Front Lines of Technology Development
Interview with Kiyokatsu Iwahashi, Director of the Technical Development Center
In What Way Rion’s Innovation Comes into
The Technical Development Center (TDC) coordinates
various business projects at Rion to help the company
continue to create the most advanced technologies and
solutions. In this issue, we interview Kiyokatsu Iwahashi,
its Director, to learn how they operate and about his future
perspectives.
IN THE BACKYARD
Interview and article by Editorial Committee
Photo by Aya Kishimoto
12
—So what do you think is an essential quality for an engineer?
I think engineers have to afford themselves a certain level of
self-respect to be successful. In other words, good engineers tend
to hate losing. [laughs] For example, on coming across a better
product from another company, an engineer has to experience
chagrin and frustration and be able to channel that frustration into
making an even better product. I believe maintaining this sense
of pride and competitiveness is essential to developing quality
products. Fundamentally, I want my engineers to take pride in
knowing everything that matters when addressing a customer
or a product. If they come across something they don’t know, I
want them to start working right away to gain the knowledge and
experience they need to become better. I think you need to have a
fairly competitive spirit, as that’s what drives engineers to continue
creating products that can be of benefit to society and help people.
Listening to the Voices of Customers
Generates Ideas That Support Society
—Does the TDC have any specific approach you consider
unique?
The center promotes what we call a 20% activity policy. That
means devoting one day of the five-day work week to independent
research, outside of the engineer’s assigned responsibilities, to
pursue interests outside current duties. One goal of this policy is
to expand the horizons of interest and to encourage the dreaming
and imaginative leaps needed to consider needs, technologies, and
products that don’t exist today. Another goal is to give engineers
time to refresh. No judgment is made on what’s done in the 20%
activities. We want our engineers to feel free, unconstrained, and
to expand their potential. The time required to take fresh perspec-
tives is essential for growth.
—Can you talk about some of the current research at the TDC
and new product development plans that will pave the way for
the future?
I can’t go into the details as most of that information is confidential,
but I can give a few examples. In the medical field, we’re pursuing
research and development on a system to restore speech to those
who have lost their vocal cords due to disease or other reasons,
a system that will enable the natural expressiveness of human
speech and appropriate intonation. Another R&D project involves
a system that will detect and monitor waterborne microorganisms.
The recent abnormal weather conditions have resulted in growing
numbers of cases of mass proliferation of microorganisms on
scales exceeding any predictions, which leads to degraded water
quality. Rion’s expertise is directly applicable to this water quality
management system and its core technologies, so I expect the pace
of technological development will speed up going forwards.
—In which directions is the TDC likely to head in the coming
years?
We have various goals, but one line of development will certainly
involve hearing aids as part of daily life in 2030. That’s a goal the
entire company is pursuing. We hope to devise a system that will
allow people who need hearing aids to be able to live entirely free of
constraints in their daily lives. Countless human communications
rely on the auditory pathway: announcements or names called out
at hospital waiting rooms, railway stations, banks, and so forth.
We want to create a society in which those who wear hearing
aids will have easy access to this information. The ideal hearing
aid meeting these requirements would involve the development
of wireless technologies or technologies linked to smartphones.
Another line of research involves the development of a series of
devices based on AI. That’s going to require gathering knowledge
and expertise in AI, so that’s one of Rion’s priority areas. Last but
not least is enhancing our approach to putting the customer first.
Rion initiates some technology and product development efforts
on its own, of course, but many efforts actually start with requests
from our customers. For example, a railway company we had been
working with for quite some time voiced the need for a system that
could enable early earthquake detection and contribute to safer
railway operations. The current system emerged from this request.
That’s how innovative technologies and products are born. We
work closely with our customers, who ask: Would it be possible to
do (such and such)? Then we set to work on finding the solution.
Being attentive to our customers is the key step in technological
development. I believe that by winning the trust of individual
customers as reliable partners we can achieve our greatest goal,
which is to provide extensive support and contributions to society.
Kiyokatsu Iwahashi
Director of the Technical Development Center.
Since joining Rion, he’s contributed to the de-
velopment of digital measurement technolo-
gies used in noise and vibration measurements
and to the development of analytical instru-
ments.Previously,heservedastheEngineering
Manager of the S&V Measuring Instrument
Department and as the Executive Officer of
the Environmental Instrument Division. He has
played key roles in various Rion breakthroughs.
13

9. See and Hear Tales of Rion Products and Daily Life!
Sound Insulation Performance
of Building Materials
Measuring the
Facility visited in this episode: Kobayasi Institute of Physical Research
14
Kobayasi Institute
of Physical Research
This institute pursues research on noise and
vibrations—road traffic noise, railway noise,
and vibration measurement—as well as
sound absorption rateand sound transmis-
sion loss measurements, various materials
testing such as
vibration damping tests of vibration con-
trol materials, and research on piezoelectric
polymer properties. It operates various ex-
perimental and research facilities, including
an anechoic room, reverberation room, and
model experiment room required for acous-
tic experiments; a low-frequency sound
experiment roomfor characteristic and eval-
uation experiments of auditory perception at
low-frequencies; an oblique incidence sound
absorption experiment room for sound ab-
sorption rate (oblique incidence sound ab-
sorption coefficient) measurement for sound
entering from specific directions; and a lab-
oratory building for architectural acoustics
testing. It focuses on studies intended to
broadly benefit society.
Multi-Channel Signal Analyzer
SA-02
This system detects and renders pass/fail
judgments on abnormal sounds and vibra-
tions on lines. Depending on the purpose,
various sensors can be selected and con-
nected to the unit, including various micro-
phones, acceleration pickups, and surface
intensity sensors. It’s won high praise from
users for its role as a frequency analyzer and
is equipped with functions for multi-channel
signal analysis, FFT analysis, and 1/1-, 1/3-,
and 1/12-octave band analysis.
How are Rion’s products used by customers?
How do they contribute to society?
For this episode, we visited the Kobayasi Institute of Physical Research,
which pursues research on noise and vibration.
Manga by Tama Tsuchiya
15

10. Hanoi
Hue
Mekong River
Phú Quốc Island
Ho Chi Minh City
I’ve been posted in Vietnam since 2018. I’d like to
write about my work and life there. When I was in
Sendai, the division head at that time was looking for
someone willing to go to Vietnam. Finding the idea
interesting, I raised my hand. In Japan, I’d always
been aware of Rion’s reputation and how that sim-
plified my job as a sales representative. So, I thought,
“I wonder how well I could do in a market where
Rion’s name has yet to be well-known. I bet it will be
a great opportunity to improve myself.” That was the
reasoning behind wanting to work abroad.
Rion has been exporting its products for several
decades now, but it wasn’t until 2016 that we really
began to try expanding sales of our medical testing
equipment in Vietnam. We have no local branch or
sales office there. To lay the foundations for working
with otorhinolaryngologists, I started by creating a
system to make audiometric testing and prescription
hearing aids available at major national and public
hospitals. I’m currently offering our services and
products on a daily basis through these hospitals. I
mainly work in Ho Chi Minh City and visit hospitals
and sales outlets in Hanoi, Hue, and other regions
for promotional and sales activities. The flight time
between Hanoi and Ho Chi Minh City is approximately
2 hours. At one time, I would fly several times a week
between the cities.
In contrast to Japan, only some hospitals in large cities
of Vietnam are capable of offering audiometric test-
ing and prescribing hearing aids. That’s why it brings
me joy every time I see a patient’s face light up when
they first try one of our hearing aids. These moments
motivate me to work harder. In Vietnam, most of the
patients are accompanied by family members, who
are worried about their loved ones, but hearing aids
bring a smile to the faces of everyone in the family.
In those moments, I’m truly glad my work involves
introducing hearing aids to people’s lives like this.
On the downside, I’ve encountered people who’ve
had impaired hearing since childhood and who’ve
never been trained in speech or language fail to com-
prehend words even after being fitted with a hearing
aid. This is totally different from the situation in Japan.
I hope the public welfare system will be improved to
expand the number of audiometric testing devices
installed, to enhance early detection and follow-up
for people with hearing impairments, and to subsidize
the purchase of hearing aids.
As I grow more familiar with the people and culture
through my work and life here, I often hear that the
current situation resembles the period of Japan’s
rapid economic growth, or ‘bubble economy’. The
pace of economic growth is truly dramatic. Each day,
I witness firsthand the growing prosperity. Reflecting
this mood, I find that people are quick to take action
and make decisions. In a business situation, the
people are really hungry, such as “No need to go
into the details. If there’s profit to be made, what
are we waiting for?” That’s their attitude. Everything
advances at a rapid pace. That’s completely different
from present day Japan. There’s much I can learn from
being here, and I think part of my job is to pass on the
knowledge to those in Japan.
I’m the only employee of Rion posted to Vietnam.
While the sense of responsibility weighs on me, there’s
also a sense of fulfillment. Through our company’s
products, I’m experiencing things I could never have
experienced back in Japan. To bring smiles to as many
people as possible and to expand our sales—those
are the two goals that motivate me.
Hearing Aids Bringing a Smile
to the Whole Family
Fitting a hearing aid at the Bach Mai Hospital, a national
hospital in Hanoi
Enjoying Vietnam food with two local Vietnamese sales staff
Taking time off on Phú Quốc Island, off the southern coast
of Vietnam
Ho Chi Minh City, with many buildings stretching into the
distance
On a cruise in Mekong River; aboard a fruit-vending boat
Vietnam
Yudai Isobe
Medical Instrument Division, posted to
Vietnam In 2018, he was posted to Vietnam
when Rion launched sales of hearing aids in
Hanoi, followedbyHoChi MinhCity.He’sin
charge of fittings and sales of hearing aids
and sales of medical testing equipment at
hospitals and sales outlets, and currently
travels around Vietnam to promote the Rion
brand and expand sales.
Here we’ll present reports by Rion staff members posted overseas,
on their work and their daily lives.
How does Rion contribute to people in foreign countries?
What’s life like abroad?
This section will be presented as a series of stories,
with one member’s story in each issue.
FROM OVERSEAS
Rion Across the Sea
16
“I like the sense of distance Kokubunji gives.
It’s not too spacious, but not too confined. The
people are warm but not meddlesome. The center
of Tokyo remains accessible, but not accessible.
Kokubunji is so perfectly located it remains free of
the fast-paced life of Tokyo. Live too far from the
center though, and there’s the risk of a suffocating
suburban life; live too close to the urban center and
there’s the risk of losing yourself in a busy city life.
That’s what I like about working in this town. You
can always find time for yourself.”
Takeuchistartsbytakingustoacafé, Honyarado. It’s
a local hideaway and icon of Kokubunji, known for
its numerous hippie communities during the 1970s.
It has a superbly crafted wooden counter table and
table seating for leisurely whiling away the hours,
and is a favorite café bar frequented by fashionable
locals—and even people from outside the town.
Takeuchi often spends his time at the café after
work.
“I used to work for an office in Ginza, which is an
exciting place just to wander around. But I think
the atmosphere there made me a bit restless.
Now that my office is located in the calmness of
Kokubunji, I feel more anchored and self-controlled
as I work. Well, a lot of the time I’m running around
the company with my arms full of paperwork.”
Next stop is Kasugai, his favorite second-hand
shop, and Yoshida Suits, a tailor’s shop. Just seeing
the nostalgic interior goods and tools from around
the world takes you back in time—a retro-modern
suit shop that functions as a retreat for reapprais-
ing your true self. Both are places you may want
to drop in on after work, and stores like these,
snuggled within the residential areas, are part of
the town’s charms.
“Kokubunji is perfect for Rion, whose style is to
continue pursuing what we believe in, regardless
of trends. Rion takes pride in calmly thinking
things through, focusing on exploring a theme, and
identifying what’s truly important. I understand
why our head office has been here ever since we
constructed our company building in this town.”
Takeuchi claims the positive office environment
is a driving force behind his work fulfillment and
coming up with fresh ideas. Listening to the sound
of the clear streams flowing through the quaint
town while strolling along Otaka-no-Michi Path
and Masugata-no-ike Pond Springs (the latter
named one of Tokyo’s 57 renowned springs) and
appreciating the village forests of Musashino in
the green conservation area of Koigakubo—this
closeness to the nature is another privilege enjoyed
by those who work in Kokubunji.
A Town of Enchantment
That Reminds You of Your Inner Self with Every New Step
❶ The invaluable joy of walking
amidgreenery ❷ Kasugai, a sec-
ond-handshop filled with goods
from the good old days from
around the world to entice buy-
ers ❸ Yoshida Suits, a tailor’s
shop with a shopfront lifted
straight from suburban London
❹ Taking a look inside Hirobe
Kaban, a leathercraft shop, and
Klang, a metal accessories shop,
to be soothed in the calming
presence of hand-crafted prod-
ucts ❺ An leather apron bag be-
ing sold at Hirobe Kaban ❻
Chatting with the owner of
Hirobe Kaban, a leathercraft
shop.The unique local characters
are one of Kokubunji’s many
charms ❼ Strolling around
Kokubunji along its many clear
streams ❽ An unexpected dis-
covery of an owl café during a
walk along a stream, something
to be set aside for future visits ❾
The interior of the Honyarado
with its clear traces of hippie cul-
ture ❿ Inside the Honyarado
café, which becomes a bar at
night
RION STAFF SHOW YOU AROUND—OUR FAVORITE TOWN, KOKUBUNJI
Strolls Around Kokubunji
In this new collaborative series of articles, each of our staff members will presents their unique take
on Kokubunji, Rion’s hometown. Today, we’ll embark on a half-day tour and immerse ourselves in this
delightful town. We’ll visit the spots locals want to keep secret and explore its many charms.
Honyarado
From its beginnings as a hangout for
free-thinking hippies, this café remains
unchanged by the currents of the
times. Today it’s a quiet, unassuming
hideaway for adults.
Kokubunji Manshion B09
18-3 Minamicho 2-chome,
Kokubunji-shi, Tokyo
My Favorite
Ryo Takeuchi
Investor & Public Relations Section. Since
joining Rion he’s been in charge of publish-
ing in-house newsletters and public rela-
tions activities for investors. He’s a member
of the Editorial Committee of the RION
Technical Journal. In his private life, he pur-
chased a second-hand apartment last year
and renovated the four-bedroom flat into
a spacious studio apartment; Ryo and his
wife have one son.
❶
❷
❹
❸
❺
❿
❻ ❼
❽ ❾
17
This issue’s theme
［Retro-Modern & Green］
Hometown!

11. The Three Business Domains of Rion
Rion’s [Activity Report]
Research Presentations/Review Articles
◎ The 2021 spring meeting of the Acoustical Society of Japan, on March 10
(Wed.), 11 (Thu.), and 12 (Fri.), 2021. Meeting held online.
Beginners’ Seminar, “Acoustics × Career Paths - What It Is Like to Have a
Career in Acoustics (in Japanese)”; Takashi Morimoto (Rion)
Present Standards for the Sound Attenuation Measurement of Hearing
Protectors; Sakae Yokoyama (Kobayasi Institute of Physical Research), Takashi
Yamasaki (Rion, Japan Hearing Protection Research Association)
Study on Vibration Acceleration Estimation Flow for Floor Structure under
Tatami; Ryuta Tomita (College of Science and Technology, Nihon University),
Yuta Goto (Takenaka Corporation, formerly the Graduate School of Science
and Technology, Nihon University), Reina Aoki (Graduate School of Science and
Technology, Nihon University), Dai Adachi (Rion)
◎ Journal of the Japan Wind Energy Association, vol. 44, no. 4, consecutive
vol. no.136 (published in Feb. 2021)
Measurement and Analysis of Noise and Vibration (in Japanese); Yasutaka
Nakajima, Tomoaki Cho, Takumi Uchida (Rion)
◎ The Environment and Measuring Technologies, March 2021 issue
Introducing New Technologies: The Latest JIS Standards and Measuring
Instruments Required to Register Measurement Certification (Sound
Pressure Level, Vibration Acceleration Level) (in Japanese); Tetsuya Ozaki
(Rion)
◎ The 2020 Award of the Director-General of the Industrial Science and
Technology Policy and Environment Bureau METI (recognizing contributors
to the operation of the metrology system)
Masaharu Ohya
◎ The 2020 Award of the Director-General of the Industrial Science and
Technology Policy and Environment Bureau (recognizing contributors to
industrial standardization)
Takashi Minakami
Exhibitions/Academic Meetings
Environment: Spring meeting of the Institute of Noise Control Engineering of
Japan (online, on Thursday, April 22, 2021)
Medical: The 122nd Annual Meeting of the ORL (Oto-Rhino-Laryngological)
Society of Japan and adjacent corporate exhibits (Kyoto International Conference
Center, from Thursday, May 13, to Saturday, May 15, 2021
https://site2.convention.co.jp/jibika122/
Environment: Automotive Engineering Exposition 2021 Yokohama (PACIFICO
Yokohama, from Wednesday, May 26, to Friday, May 28, 2021)
https://expo.jsae.or.jp/
Environment: Automotive Engineering Exposition 2021 Nagoya (Portmesse
Nagoya, from Wednesday, June 30, to Friday, July 2, 2021)
http://expo-nagoya.jsae.or.jp/
Seminars
Rion holds seminars on sound and vibration around Japan.
Visit the website to the right to check for dates, venues, programs,
and other details.
https://svmeas.rion.co.jp/event/all
Rion’s name is a combination of “ri” for rigaku (physics) and “on” for
Onkyogaku (acoustics). The name reflects our devotion to pioneering
work in fields associated with acoustics, with its deep roots in physics.
Our company was founded in 1944 to commercialize the results of
research carried out at the Kobayasi Institute of Physical Research, an
institute dedicated to studies in physics and acoustics.
Our company’s acoustic and vibration technologies have benefitted
society in various fields during the 77 years since its foundation. We’re
currently active in three business domains to contribute to human
comfort and happiness and to the advancement of industries.
Particle Counters
Rion offers various types of particle counters in support
of Japan’s manufacturing industries. These range from
the airborne particle counters essential to cleanroom
operations in the electronics industry to liquid-borne
particle counters that ensure the highest standards of cleanliness
as required in the process of manufacturing pharmaceuticals
and foodstuffs. Our products are highly acclaimed for meeting
the evolving needs of our customers, including rapid response to
governmental and industry regulations and standards, meeting
demands for networked standards, and enabling operations in
tandem with production systems.
Medical Instruments
Seventy years have passed since the first mass-produced
hearing aid went on the market. Rion has continued
to produce industry-leading hearing aids, applying
its advanced technologies to realize more compact
designs, digital processing, and waterproof construction, to
help users with verbal communication. The various medical
testing equipment marketed by Rion have won high acclaim
not just for their advanced functions, but for their durability
and user-friendliness and for the support system we’ve estab-
lished across the country.
Environmental Instruments
Rion mainly produces sound and vibration measuring
instruments, including sound level meters used to monitor
noise from road traffic, factories, construction sites, and
aircraft; vibration meters essential for performance testing
in maintenance, inspections of factory facilities, product
development, and vibration pollution countermeasures; and
seismometers that help maintain the social infrastructure. Rion’s
sound and vibration measuring instruments offer ideal solutions
to precisely meet each of the diverse needs related to environ-
mental administration and industry.
“Ri”Is for Rigaku + “On”Is for Onkyogaku
(Physics) (Acoustics)
18
2020
Award of the Director-General of the Industrial
Science and Technology Policy and Environment
Bureau METI (recognizing contributors to the
operation of the metrology system)
Masaharu Ohya
AWARDS!
2020
Award of the Director-General of the Industrial
Science and Technology Policy and Environment
Bureau METI (recognizing contributors to the
operation of the metrology system)
Takashi Minakami
Masaharu Ohya of the Business Planning Department, Environmental Instru-
ment Division received the 2020 Award of the Director-General of the Industrial
Science and Technology Policy and Environment Bureau, METI (recognizing
contributors to the operation of the metrology system). METI grants this award
to recognize individuals who have made meritorious contributions to the oper-
ation of metrology systems over the years. Ohya is the first individual from Rion
to receive the award as a contributor to the operation of metrology systems.
Ohya took part in work to revise cabinet and ministerial orders associated with
the Measurement Act for measuring instruments and has worked to formulate
and internationalize related Japan Industrial Standards (JIS). He has been rec-
ognized for his contributions in supporting and advancing metrology systems
in Japan.
Post Award Interview
Q1. How did you feel about the award?
For many years, from the days of my predecessors, Rion has worked with and
contributed to the metrology-related administrative authority involved in the
operation of metrology systems. This award recognizes Rion’s sustained efforts
to date. I’m truly honored.
Q2. What were your contributions to the JIS formulation?
In 2015, revisions to the Measurement Act and the Regulations on Calibration
and Inspection of Specified Measuring Instruments were made regarding
sound level meters and vibration level meters. Specifications were harmonized
with the IEC, an international standard, and with JIS. This marked the most
significant revisions since sound level meters and vibration level meters became
specified measuring instruments. Various discussions had taken place in the
past regarding the need for revisions, but for various reasons, they never
went beyond discussions. The latest revisions had been strongly desired by
the metrology-related administrative authority. JIS was revised in 2020 to
provide wider flexibility in implementing the Measurement Act. In line with
the formulation of the standards and revisions of the regulations, I was put
in charge of practical tasks as a member of the committee for the drafting of
the JIS standards and a senior member of an associated subcommittee. I was
also responsible for representing the industry when submitting a statement of
opinions to the administrative branch. What I discovered through my activities
is that anything is possible as long as everyone works to fulfill their roles in their
respective positions. We had numerous discussions with the METI Metrology
Policy Office and the National Institute of Advanced Industrial Science and
Technology (AIST) in considering various matters such as potential legal
contradictions, other laws, and regulations that might be affected, whether the
revisions would adversely impact users, and what to do if they did. I was quite
impressed by how everyone went about their duties and how we functioned
as a team.
Q3. What are your thoughts on your future activities?
Our sound level meters and vibration level meters, the main products of the
Environmental Instrument Division, have evolved alongside metrology policies.
People tend to think that laws and regulations are determined by the govern-
ment and the only role for citizens is to comply. At Rion, we pride ourselves
on being the most informed on the optimal vision for measuring instruments,
their management, and the circumstances of their users. This time, I think Rion
fulfilled its calling. I hope we’ll continue to do so. Rion has also produced staff
members to serve on international standardization committees. As a Rion staff
member, I hope I can expand our influence in metrology policymaking and
make contributions not just in Japan, but around the world.
Takashi Minakami of the Particle Counter Sensor Development Section, Com-
ponent Technology Development Department at the Technical Development
Center received the Award of the Director-General of the Industrial Science
and Technology Policy and Environment Bureau, METI in 2020. The award is
presented to individuals and organizations providing distinguished service to
the International Organization for Standardization (ISO) and the International
Electrotechnical Commission (IEC) in the drafting of international standards
and who have made outstanding contributions to standardization activities in
the drafting of domestic standards (JIS). Since 2011, Minakami has served for
nine years on the committee for ISO*1
/TC 24 (Particle characterization including
sieving)/SC 4 (Particle characterization). Most notably, he served as the shadow
convener*2
and project leader for ISO/TC 24/SC 4/WG 9 (Single particle light
interaction methods) and as the head of the liaison committee in Japan. He
participated in the drafting of both international and domestic standards for
particle characterization and played a leading role in the development and
maintenance of standards associated with particle counters. Through these
activities, he established a unified international standard for particle counter
performance, as well as a precise inspection method that broadens the range
of tested particle size, thereby contributing to improved cleanliness in various
environments.
*1: Organization charged with setting various international standards (ISO
standards); currently has 162 member states (as of the end of December
2018)
*2: Vice-chairperson of WG (Working Group)
Post Award Interview
Q1. You’ve spent almost nine years working to develop international
standards. What’s your most vivid memory?
I remember how busy I was between the time I first participated as a com-
mittee member in the international meeting of ISO and the next meeting. My
predecessor, Mr. Kazuo Ichijo, had just passed away in July 2011. The next
ISO meeting (in Edinburgh, Scotland) was scheduled for early September, just
a month and a half away. I was chosen to be his last-minute replacement to
attend the meeting. At the meeting, it was decided that the vice-chairperson,
who was British, would be promoted to chairman, and I was to become the new
vice-chairperson. Voting on the revision of ISO standards for particle counters
stipulated in 2007 had just occurred. It had been decided while Mr. Ichijo was
still alive that the revision work was to proceed. And I was responsible for draft-
ing the revised standards for the next international meeting, which was to take
place six months after my return to Japan. I was new to this; things didn’t go
smoothly at first. In addition, I couldn’t ignore my other duties, which involved
new product development. I would come into my office very early every day to
work on the draft for the standards, then work on developing new products
during the day.
Q2. What are your thoughts on your future activities?
The description of the Award of the Director-General of the Industrial Science
and Technology Policy and Environment Bureau says the award recognizes
“individuals who have contributed to the standardization and conformance
assessment activities and who are expected to continue their outstanding activ-
ities in the future.” I hope to live up to those expectations. Another important
task is to give back to Rion what I’ve learned from this activity and to foster the
generation of engineers who will come after me.
19