NIL

1. ALL INDIA INSTITUTE OF LOCAL SELF
GOVERNMENT
DELHI
“ Noise Concepts for Paramedical”
DR.P.P.SINGH
By
Dr. P.P.SINGH
Faculty AIILSGD
Ex Medical Superintendent Cum Consultant pathologist HRH Delhi
Ex. Director India Population Project 8 Delhi..
SOURCE FROM BOOKS OPF AIILSD

2. •NOISE
-- IS AN UNWANTED SOUND.
--ARE UNPLEASANT, ANNOYING &
DISTRACTING SOUNDS.
-- SOUND WHICH ARE LOUD AND
UNPLEASANT .
-- IS THE WRONG SOUND , IN WRONG PLACE
AT THE WRONG TIME.

3. COMMON TERMS USED IN THE STUDY O0F NOISE.
1. ACOUSTICS : SCIENCE OF SOUND & ITS
EFFECT.
2. CONDENSATION : AREA OF COMPRESSION
IN SOUND.
3.RAREFACTION : AREA OF EXPANSION IN
SOUND .
4.FREQUENCY : NUMBERS OF CONDENSATION
& RAREFACTIONS PRODUCED BY VIBRATION IN
ONE SECOND.
5.HERTZ : UNIT TO MEASURE FREQUENCY.
ONE HERTZ MEANS ONE CYCLE PER SECOND.

4. 6. DECIBEL ; UNIT TO MEASURE THE INTENSITY OF
SOUND .(A 3000 HERTZ TONE IS THE WEAKEST SOUND
THAT A NORMAL EAR CAN HEAR & IT ZERO DECIBEL.)
7. PITCH : IS DEGREE OF HIGHNESS OR LOWNESS
OF SOUND AS PERCEIVED BY LISTENER.
8.SOUND QUALITY : IS THE CHARACTERISTIC OF
MUSICAL SOUNDS.
9. INFRA SOUND : SOUND WITH FREQUENCIES
BELOW THE RANGE OF HUMAN HEARING.
10. ULTRASOUND : SOUND WITH FREQUENCIES
ABOVE THE RANGE OF HUMAN HEARING.

5. SOUND / NOISE - CAN BE DESCRIBED IN:-
I, FREQUENCY AND PITCH.
II, INTENSITY & LOUDNESS.
III, QUALITY
NOISE MEASURED IN DECIBEL.
“0” DECIBEL SOUND CAN BE JUST HEARD.
“120” DECIBEL SOUND CAN BE FELT AS WAVE.
“140” DECIBEL OR MORE CAN CAUSE PAIN IN
EAR.
“ WHISPER “ AMOUNT TO ABOUT 20 DECIBEL.
“40” DECIBEL IS THE ORDINARY CONVERSATION .

6. SOME FACTS ABOUT SOUND.
Sound travel faster through liquids & soiled than
Air.
Sound travels 4 time faster in water and 15
times faster through in steel.
The speed through air increases as the air
temperature rises.
Sound travels 331 meters (1085 feet) per
second through air at 0oC and 386 meters (1268
feet) per second at 100 C

7. SOUND LEVELS OF SOME NOISE:-
-----------------------------------------------------------------------------------------------
----
Sources intensity/ decibel
Sensation
-----------------------------------------------------------------------------------------------
----1.Plane takeoff 150
Extremely Loud
2.Boiler Maker Shop 120 Extremely loud
3.Pneumatic drill 110 Very
loud
4.Siren 100 Fairly loud
5.Children Crying 80 Fairly
loud.
6. radio/ TV 80 Loud.
7.Canteen 70 Loud
8.Public Library 40 Quiet
9.Class room 40 Quiet.
10. Whispering 20 Just audible
11.Silence 0 Inaudible

8. EFFECT OF NOISE.
ON ANIMALS;- TEMPORARY RISE IN BREATHING
RATE, BP.
DEGENERATION OF HAIR CELL ETC.
ON HUMAN:-1. SHORT EXPOSURE OF HIGH
INTENSITY CAUSES RUPTURE
OF EAR DRUM.
2. PROLONGED EXPOSURE – LOSS
OF HEARING. FATIGUE,
HEADACHES, IRRITABILITY,
NAUSEA AND TENSION , HIGH BP.
TINNITUS :- LOSS OF HEARING DUE TO OLD AGE.
NORMALLY ½ DECIBEL PER YEAR AFTER 40 YEARS
OF AGE.

9. NON-AUDITORY EFFECT
1.INTERFERENCE WITH SPEECH.
2. IRRITABILITY.
3. LOSS OF EFFICIENCY
PERFORMANCE AND ACCIDENTS.
MEASUREMENT OF NOISE :- IN
ENVIRONMENT BY NOISE METRE. AND IN
HUMAN BODY – BY AUDIOGRAMS

10. CONTROL OF NOISE
1. CONTROL OF SOURCE: PARTS WHERE
NOISE IS PRODUCED SUCH AS MOVING PART, FAN,
ELECTRIC PUMPS, AIR COMPRESSOR, PRINTING
PRESS MACHINE ETC. – CAN BE REDUCED BY
ISOLATION.
2.CONTROL OF PATH : IT IS THE DIRECTION
TAKEN BY SOUND , IN BUILDINGS THICK WALL,
SEALED DOORS & WINDOWS. MAKING SOUND
PROOF ROOMS AND VARIOUS OTHER MEANS TO
BLOCK – MAKING INSULATION.
3. CONTROL OF RECEIVER : EAR MUFFS, EAR
PLUGS

11. LEGAL MEASURES :-
1, PERMISSIBLE LEVEL OF NOISE = 90DECIBEL FOR 8 HR
SHIFT.
2.NOISE INCLUDED DEAFNESS IS A MODIFIABLE DISEASE TO
FACTORY INSPECTOR.
3.NOISE INDUCED DEAFNESS IS A COMPENSABLE DISEASE .
OTHER MEASURES:
A) PROSPECTIVE PLANNING OF CITIES.
B) CONTROL OF VEHICULAR TRAFFIC.
C) IMPROVING ACOUSTIC INSULATION OF BUILDINGS.
D) INDUSTRIES , RAILWAYS TO INCLUDE NOISE CONTROL
MEASURE AT ITS ROOT LEVEL.
E) HEALTH EDUCATION TO PEOPLE.

12. ACCEPTABLE NOISE LEVEL IN DECIBELS:
RESIDENTIAL
-BED ROOM 25
-LIVING ROOM 40
COMMERCIAL
- OFFICE 35-45
-RESTAURANTS 40-60
INDUSTRIES
-WORKSHOP 40-60
-LABORATORY 40-50
EDUCATIONAL
-CLASS ROOM 30-40
-LIBRARY 35-45
HOSPITAL WARD 20-35