Fixing Sound With Effects
Many audio effects are not used to actually distort or alter the audio in a creative and aesthetic way. Since much of audio mixing and audio post-production is actually in the service of fixing mistakes that occurred in audio recording, the same is true of many of these audio effects that are implemented. Much of the problems that occur during audio recording happen when a consistent sound that is unintended creeps in. This sound can be in the form of a static tone or a low hum of some sorts, which can often come from interference in unbalanced cables or other problems with the sound recording equipment. There are a number of different ways to try and approach this during audio post-production, and there are a number of different audio effects that can be used depending on the type of sound that has made its way into the audio track. One of the main audio effects that is for that is called audio gating.
Gating refers to a general processer that puts a limit on the range of sound that is displayed, which in essence puts a "gate" on it. This audio gating can be used if there is problems at certain high or low tones in the audio track as it came out. The process of audio gating will essentially render certain tones unable to come through, which forces a mute onto them. What would happen to the audio track that had the audio gating applied to it is that the main focus tones would be allowed through while the gated ones were kept completely silent. For example, if you have the audio recorded of someone playing basketball and there was a low hum in it the gating would eliminate this. The sounds of the basketball would still come through for the most part, but there would be silence among the low pitch sounds.
Audio gating is not necessarily just an audio post-production tool and you may notice that you can do this with your actual audio equipment. This can be a good option if there are consistent tone sounds in the actual environment that cannot be eliminated, such as the machine drone of appliances in a kitchen area. Gating is also often united with reverb, which is the audio decay that happens from when the noise is inspired by an action and when it ceases to exist. If gating is applied to the reverb you can actual cut off portions of this decay and have an artificial cleanliness to the sound. Audio gating can be applied to a whole host of situations and other audio effects, each one will produce a different effect. You may want to negotiate between gating and other corrective audio effects, like a high pass filter.