Once you have recorded a large amount of material intended to be used as sound effects, the next step in creating a sound effect library is to edit this raw audio. You will need an audio editing software that will allow you to cut, fade in/out, normalize, and eq your tracks. There are many professional digital audio workstations (DAWs) out there for purchase and also several useful freewares easily found on the internet.
The first step in editing your sounds is to import all of the various raw .wav recordings into your software. This can be done one at a time but for efficiency I usually import 40 audio tracks at once and then solo each track, in other words muting all but one tracks. Once you’ve imported all of your tracks and you are ready to edit and bounce your edits down to completed sound effects. These following tips should help ease your experience and provide the best sound effects possible.
1. The first step is to normalize each sample. This makes the audio as loud as possible by increasing the amplitude of the highest point on your recording to the highest point possible.
2. Secondly, some frequencies may affect the quality of your sound effect and you should use eq to eradicate these sonic culprits. A great sounding bird chirp, for example, may be compromised by an offending air conditioner. But, by cutting all frequencies below 2,000 Hz you can get rid of the AC and keep the lovely bird sound.
3. When your sound is normalized and cleaned up with eq find a clean beginning point to the sound and either create a fade-out or more desirably let the natural reverb ring out for 1-2 seconds.
4. Bounce your sound down to a 48k 24bit .wav file for video editing. 48k 24bit are high quality files that are valued by sound effect libraries and licensees who pay good money to use sound effects in their productions.
5. In order to increase your amount of products make as many versions of each recording as possible. For example, if a recording has a cat meowing 25 times, make sound effects with one meow, two meows, 5 meows, 8 meows etc. while changing up the combination of meows. This process will easily give you 50 or more sound effects from one sequence of cat meows.
6. You can further increase your number of effects by using pitch shift or other filters on each sound sample. For instance, the sound of a stream can be pitch shifted up to make it sound lighter and less tumultuous and pitch shifted down to make it sound larger and deeper.
With a little knowledge of audio editing, simply follow the above advice to transform your audio samples into professional quality sound effects for licensing in media productions.