1. Indoor Acoustics
Principles of Sound and Acoustics
What Is Sound
The dictionary describes sound as, vibrations caused by a medium (which could be
either a gas, liquid or solid) travelling through the air or another medium, and is
heard when theses vibrations reach another person or animals ear (for example,
when a piano key is struck, the movement of the string disturbs the surrounding
medium, air, resulting to the displacement of molecules.Similar to light, sound is a
wave (pressure wave), these sound waves pass through the objects or materials that
create the sound, or where the sound comes from.
According to- (http://www.jiscdigitalmedia.ac.uk/guide/the-physical-principles-of-
sound/)
Sound has three stages which affect how it is perceived by a listener.
1. The initial character is shaped by the properties of the sound source (i.e. an
instruments' material and shape) and its excitation, such as being hit, plucked or
breathed into.
2. The environment and the mediums which sound travels through to the listener.
For example, a shout heard in a canyon sounds different than if heard in a small
room, or through a pair of speakers. See section Elementary Acoustics)
3. The listening conditions applied by the listener. The individuals subjective
perception of sound as well as their physical condition (i.e. the shape of the outer
ears, or someone's age), affects how sound is perceived by the listener (this is
discussed in the section, Sound and the Ear)
Sound has a massive variety of uses that effect human and animal’s everyday lives,
such as;
Animals use and analyse sound to find food and run away from predators
It can be used as a method to find gas and/or oil.
It’s used to examine a baby’s condition in the womb, and study earthquakes and
climate change

2. Acoustics
Acoustics is the science/discipline of sound. There is a large variety of different kinds
of sounds and each one affects our lives in different ways. Sound is our key and most
common form of communication, and acoustics are significant for creating and
performing musical instruments in concert halls, for surround sound stereo and
hearing aids.
Studio Based Acoustics
A majority of recording studios always suffer the issue of having impressive and expensive
instruments and devices, but not having a good (silent enough) recording studio to record
high quality productions, as it’s hard to remember to focus on buying an acoustic
environment (room), that won’t cause issues such as sound leakage, disruptive monitoring
viewpoint, or disturbing recordings from and by neighbours, and generally affecting the
quality of the production from a listener point of view, when purchasing a recording studio on
a budget. Within the subject matter of recording studios, recording within a controlled
environment/room, that has been built and designed correctly is likely to produce sound that
is more accurate, without using too many special effects or devices to enhance the recording
quality.
Live Room
A recording studio typically consists of a live room (a.k.a studio), this is the room in which
live instrumentals and vocalists perform. This room is the most soundproof room in the
recording studio, as other sound doesn’t leak through or out without the demand of the
control room (This is the room in which the equipment and electronic devices and controls
are kept. There are also smaller rooms called isolation booths, which mainly accommodate
loud instrumentals such as, electric guitars and drums.

3. Dead room
Dead rooms are referred to as dead rooms for the fact that they have very little or no
reverberation/echo of their own, these rooms are in almost complete silence, which is why
their referred to as ‘Dead Rooms’, dead rooms may be perceived as a room that consist of in
beats and no interruptions in the background, dead rooms are best used by vocal artists as
they can capture the clearest and best sound as it doesn’t consist of any interruptive sounds
(echo and reverberation).
Surface types
Studio walls have odd patterns to make it harder for the sound to travel through, its important,
that sound cannot travel through walls, as it cause sound leaking, disruption of recording etc.
this can be tricky as sound waves travel frequently, they eventually hit obstacles,the
percentage of the sound isreflected and the rest is absorbed, and passed through whatever the
material is. An echo or reproduction of the sound can be heard if the sound reflects off a
smoothflat surface, thisis why. It is designed for the sound to be capturedand absorbedin.
Reverberation
Reverberation is the perseverance of sound in a particular area or space a period after the
original sound has been produced. Reverberation is caused by sound being produced in
abounded space or area, resulting to a large number ofechoes to compile up and then slowly
decease due to the walls or air absorbing the sound.
Sound proofing
There are numerousand simple approaches to reducing sound for whatever reason, these
include:
Increasing the distance between source andreceiver,
Using noise barriers to reflect or absorb the energy of the sound waves,
using dampingassemblies such as sound baffles

4. Outdoor Acoustics
Sound bites
Often incorrectly referred to as sound-bites, sound bites are short clips of speech or music
extracted or trimmed from a longer piece of audio, often used to advertise or exemplify the
full length piece.
Background Atmosphere
It is extremely important to know exactly where you need to record depending on what
exactly it is you would like to record. For example, if you want to record a scene within a
café you cannot record in the woods as the background atmosphere is different as there are
different noises.
Unwanted Noise
Unwanted noise is the noise in the background of a recording or audio track, that shouldn’t be
there, for example vocals recorded on the street may be occasionally interrupted by noisy
individuals or moving transport, unwanted noise can be avoided by recording in a controlled
and extremely silent room.

5. Unwanted Ambience
Similar to unwanted noise, unwanted ambience is background sounds, which should not be in
a certainrecording; unwanted ambience is most likely in the busiest environments such as
bars, clubs or motorways.
Wind noise
When recording with a microphone (especially outdoors) using a wind shield is a key method
to avoiding wind interruptions (which can seriously harm the quality and clarity of your
recording), the majority of microphones that are specially built for this are called boom
microphones.