Organic Sound
The term organic sound refers to the capturing or manipulation of an audio signal modeled to replicate the audio image of a natural source. Organic sound can be used to create a more humanized texture to some elements of music and sound design. Adding organic sound elements into your mix can create a certain depth to the sound that can be used to simulate the way one might perceive natural ambient sounds in everyday life.
Organic Sound in Music
A lot of today's popular music relies heavily on the use of synthesizers and other electronic sounds in their arrangements. The problem with most sample libraries is the lack of natural overtones that are lost in the original recording and editing process when the samples are being created. This is what gives the sound an artificial electronic quality.
Electronic Music
To avoid creating this artificial element in a mix, producers of electronic music will add certain organic sounds to their projects to enhance the sound. Adding these organic sounds to a mostly electronic arrangement will make up for the lack of natural overtones that have been filtered out in the sampling (signal processing) process, resulting in a more intimate listening experience that allows the human ear to respond more naturally to artificial synthesized sounds that our ears may not be accustomed to process.
Popular Production Techniques
There are many ways to achieve this natural, organic ambiance to enhance certain electronic elements in an arrangement.
Analog
By rerouting an audio signal out of your sequencer and into an out-board or analog signal processors such as pre-amps, compressors, amplifiers, etc., your are adding this new element of realism to your signal [1]. When using a pre-amp or compressor you are able to gain a little bit more warmth to your signal and sometimes, depending on how you decide to use the equipment, a bit of light distortion. This will give your signal a bit more original character. Re-amping your signal is also a great way to add new sound qualities. If you re-route your track out of your sequencer and into, say, a guitar amplifier, you are now able to add a new tone to your synthesizer sounds, and by micing the amp to feed the signal back to your sequence you gain a new room sound that will add a new, more natural depth to your signal. After adding signal processing to your audio, you can sometimes lose some of the depth of your signal. Re-amping your signal add a new natural room sound to your mix creating an illusion of how the signal would have responded had it actually been recorded as audio. Mixing the natural room sounds with artificial reverb can mask the original synthesizer track, originally seeming unnatural to the human ear, with natural presence of reverb that is quite pleasant to the ear [2].
Digital
If you do not have access to out-board signal processing, there are options for you to enhance your sound digitally within your sequencer as well. Most sequencing programs come with some stock processing plug-ins, things such as compression, equalizers, reverb, and distortion. Though software plug-ins are a lesser alternative to analog signal processors, you can still use them to manipulate your audio signal and gain a new, more organic sound. Changing certain frequency responses in an equalizer is a great way to enhance your sound digitally.
Organic Sound in Film
In the production of a film, it is the job of the sound designer to recreate the intimate audio experience of what's going on in a scene in order for the viewer to enjoy the full experience of the production. In order to achieve this intimacy, the sound designer will need to put themselves in a setting similar to that of the scene they are designing sound for and manifest sound elements of nature, whether it be a soft airy motion resembling that of slight breeze, or low hum or buzz that could be a bee's nest in somebody's back yard. An experienced sound designer will also take into account things that could be producing sound off screen such as birds chirping, dogs barking, a car engine, basically anything you think you might hear in a situation such as the one on screen [3]. Motion must also be taken into consideration when designing sound for picture. If the subject on screen is in motion, techniques such as panning (audio) and volume automation should be considered, as well as more technical aspects of sound such as the doppler effect.
Surround Sound
When mixing the audio for a motion picture in surround sound it allows the mix engineer to create this new aspect of depth in the sound. They are able to create a new 3D image of sound that the human ear will respond to in a more detailed, intimate way to go along with the on-screen visual. When you think of the elements of organic sound that are going to be added to a film, the purpose is to essentially allow the viewer a first hand experience of a certain character or scene. This 3D image created by surround sound allows editors and mix engineers to work with the sound designers and foley artists on the placement of the audio source in the surround sound image. By utilizing these mix techniques, sound designers are able to acutely pin point which direction they want the sound source to come from. This idea of 3D sound imaging allows artist to now recreate an audio experience similar to the way the human ear would process the sound in the original environment and context of a scene.