Professional sound recording software provides a range of effect and processing options that are particularly useful for improving the overall quality of narration files. The ones that I typically use are:
- Noise gates – this is a processing tool that allows you to set a lower level threshold for the sound, and then mute any sound that occurs below that level, in the space between words and sentences. Used properly, it can help make your recording sound like it was done in a well soundproofed area, because listeners hear silence in the spaces between statements, while the room sound is mostly masked by the (much louder) sound of your voice. It can take some experimentation to set a gate properly, and it will not cover up undesirable room sounds perfectly, but it can really help clean up a recording.
- Equalization – EQ can be used to (slightly) reduce a continuous noise issue (such as HVAC hum), or to brighten up a dull sounding recording to increase intelligibility. It can also be used to (slightly) fix the sound of excessive room reverberation.
- Reverb – you can enhance a signal that is too dry by (sparingly) using a little bit of reverb (select small bright room, quick decay).
- Time compression/expansion – though I have rarely needed to use it, preferring to time the performance to the visual, narrators can use this function to adjust the duration of a narration segment to match the duration of a visual event, such as an animation. Note that this can result in some artifacts that can make the segment less usable, but it is worth a try to attempt to fix a segment that is too long or too short.
Most recording software includes these types of processing effects and other processing that is intended to address specific needs, but for most cases, they are not that useful for narration, and can distract from the narrative impact if overused.