Audio Report

What is sound?

Sound is a change in air pressure that creates vibrations. These vibrations then travel to the ear which the brain interprets into sound. Sound is measured in Hertz, KiloHertz and decibels. The higher the sound, the higher the pitch, lower the pitch, the lower the sound. Frequency is the frequency of the sound waves, The louder the sound, the more frequency of waves. 

Acoustics is how the sound travels, for example Indoor acoustics is how the sound travels with a room. Does it bounce and echo? Or does it stop creating no reverberation? Acoustics can be manipulated through the types of surfaces used within a room, such as having tiles or wood to make the sound bounce, or it could be rugs and carpets to trap the sound. However, the properties of the room can also influence this, walls that are slightly curbed causes the sound to bounce off in multiple directions which changes the sound opposed to sound that just bounces backwards and forwards off of a wall.

In the media industry, there are two types of recording studios that are used, each having their own advantages and disadvantages to their use. The first is a Dead Room. this type of recording studio will most likely be used for the recording of dialogue for animation films. This is because, due to the way the room is designed, there is no echo. This means that the you will get a clear, crisp sound that can then be altered depending on what the film is. How this happens is because the walls of a dead room are soundproofed, as well as the ceiling and the walls. This means that sound is absorbed rather than it bouncing and travelling back to the microphone. A disadvantage of a dead room, however is that they are difficult, and not cost effective to create. Dead rooms are not cost effective due to the different materials that need to be used in order to create it. This can be cone shaped foam to catch sound on the ceilings and walls. These materials can become expensive and may not gain back their worth in revenue for the studio as dead rooms are not used for music.  In the 1970’s, dead rooms were used for studio recordings of musical tracks, however many artists felt that these recordings were hollow and lifeless. An example of an artist is the AC/DC band who in the end refused to use a dead room for recordings as it made their tracks sound dry. An example of a track where this is prominent is ‘It’s a long way to the top’. Although, the recording method’s used during this era could have also influenced how the recording sounded. For example, by recording instruments individually from each other as well as inserting the microphone up close to the instrument rather than the overall sound of the room, this created a lifeless feel as there was no interaction between instruments. 

The opposite of a dead room is a live room.

A live room’s purpose is to have the sound echo and reflect sound off of the walls, an example of when a live room is used is for studio recordings of music tracks. A live room is designed with surfaces that reflect sound rather than absorb it, an example would be hard wood floors and tiled walls. Sound recorded within a live room has a fuller and thicker feel to the sound. Live rooms started to be used more commercially in the 1970’s. By using a live room, the sound bounces and reverbs.

Another important part of the recording process is the surface types and properties within the room. The surface types within the recording studio can affect the recording itself. For example, using hard surfaces such as wood or tiles will cause the sound to reflect off of the surfaces. This causes an echo which can be picked up by the microphones. These surfaces are used within live rooms to add a fuller sound to the recording. In a dead room, however, surfaces such as rugs and carpets are used to trap the sound to stop it bouncing off the walls and being picked up by the microphones.

Reverberation of the sound is also important when using indoor recording. When a sound bounces off of a surface, it may stay in the room even when the original sound has disappeared. It continues to bounce and echo even when the original sound is gone.

Soundproofing is very important when recording, both to make sure that no sound leaks out but also that no sound leaks in. In the control room, it is important that no sound reaches the room in order to ensure that the producers are hearing the purest sound possible and have no echo affecting what they are listening to. This ensures that the best quality sound is used. However, it is just as important to ensure that no sound enters the studio. If sound enters the studio, it can be possible caught by the microphones, this means that the sound can be altered and ruin a good recording, therefore good soundproofing is a priority when recording. 

Outdoor acoustics is, you guessed it, sound recorded outdoor. Now there are 6 important terms to keep in mind when thinking about outdoor acoustics. These are; actuality, sound bites, background atmosphere, unwanted noise, unwanted ambience and wind noise. Let’s go through them, one by one!

Actuality, in dictionary terms, is the state of existing in reality. But we are not looking at dictionary terms, we are looking at sound. Actuality is used in TV audio, this is used to make the scene more realistic by adding extra sounds such as a dull fan or background car sounds. This stops the show sounding clinical.


A sounds bite is a small audio clip of speech or music. These are used as samples, or to promote something. For example, Sound bites are used during presidential campaigns in america to grab the attention of the audience. They were first used in the 1930’s with the average length being 40 seconds, however as time has progressed it have been sliced down to just under 8 seconds. A sound bite is useful as they are an effective way to convey important segments of a speech concisely rather than having to play the entire speech.  However, the problem with soundbites is that you don’t always understand the context of the statement, this could lead to a misunderstanding of meaning.

Background Atmosphere:.

Each location has distinct and subtle sounds created by its environment, such as wildlife, rain, distant traffic. By adding background atmosphere, you are adding these sounds the scene becomes more realistic as well as filling the empty space within the sound.

In recording, unwanted noise is a great concern. However it cannot be completely erased from a recording. So the best thing to do is to get rid of the noise in the room. An example of unwanted noise is electrical hums, fans whirring and clocks. This is also unwanted ambience. These are the sounds that you don’t want in a recording.

Finally is wind noise, this is when recording outside the microphone picks up the wind. This can cause a whooshing sound in the recording and muffles any other sound. There are many ways to get rid of wind noise, one being to put a cover on the microphone, this stops the microphone from picking up the wind noise whilst still recording other sounds. An example of when recording has been an issue outdoors is Jamaica Inn which was aired on the BBC. Due to wind noise and overuse of background ambience, it was difficult to hear the actors. The BBC then ‘attracted a total of 2,182 complaints about mumbled dialogue.’ BBC also admitted that by overlaying music on top of the mumbled speech, wind noise and ambience caused the dialogue to be undetectable as it was droned out by other factors. This shows the significance of using sound equipment wisely in order to get the best quality recordings.

Simulated acoustics

Simulated acoustics are essentially sounds which are modified post production such as effects, compression and processors. Simulated sounds are now commonly used post production and in music. Modern artists now rely on simulated acoustics as the basis of their music, one example is Skrillex.  A lot of recording studios record dry sounds and then add effects to make the piece sound heavier and thicker. One example of a song where this is used is Skrillex Bangarang where they used many different effects layered on top of each other to create a heavy fuller sounding track.
Compression is used to lower the volume of a loud recording such as a gunshot, as well as making quieter sounds louder and more pronounced. This creates a much more balanced sound which creates a more harmonious listening experience. Limiting is also used to ensure there is no distortion of sound when a sound is too loud to be recorded by the microphone, an example is a gunshot. Compression and limiting is used together to ensure that the sound is both balanced and not distorted, by using this the audience can experience a better quality sound which also makes listening to it enjoyable.

Processors is another part of simulated acoustics. These are used to alter the pitch of vocals as well as instrumental recordings. Processors are used in radio, for example, for when a caller or speaker wish to remain anonymous to the audience in fear of retaliation or retribution. Processors can also be used to alter a music track. On YouTube, a popular musical genre is Night-core. This is when a music track is altered by a third party to make the voice higher as well as the instrumental. An example is ‘A Team’ by Ed Sheeran which was altered to be night-core. It then sounded as if it had been sung by a girl.

Time delay is an audio effect which records an input signal into an audio storage before playing it back after a set period of time, this signal may be played back multiple times or into the recording again to create a repeating decaying echo. It could also be used in radio when live for when members of the audience call in. This is to ensure that the speaker doesn’t swear or blaspheme live and offend anybody. 

Surround sound uses a range of techniques as to enrich the sound reproduction quality of an audio source. Surround sound is characterized by listener location or a sweet spot where audio effects work best. An example of where surround sound can be used is in cinemas, by placing various speakers around the room cinemas are able to create an immersive feeling into the movie being shown. An example of a film where this was used well was ‘Avengers: Age of Ultron’. By using surround sound and a ‘Left ear’ ‘Right ear’ theory, they were able to make sounds come out of the relevant speaker where it shows in the film.

Mono is used to refer to anything single. So, mono stereo is one speaker, which is the lowest quality sound system. Stereo is short for stereophonic which refers to a method of sound production in which an attempt is made to create the illusion of directionality of sound. This is usually achieved by using two or more audio channels through a configuration of two loudspeakers.

Effects units are used to add effects to the sound, such as echo and pitch changes. This makes the sound thicker and fuller. By using this, you are manipulating the sound and this can change the meaning and feeling of the sound. You can also influence the acoustics of the sound in order to create, again, a fuller, thicker sound. 

Phase is when more than one channel is used to record sounds, and so they can cancel each other out depending on the amplitude and volume. This can be because of the actual waves themselves or if the wiring of the speakers is incorrect which leads to the sound being cancelled out. This is called out of phase. This can happen at concerts or in a person’s own home. In many cases, people presume that the speakers are just broken when it could be fixed.



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