When you are speaking, the higher sound levels of your voice will mostly cover up the lower level ambient noise present within the room. You can hear it if you are looking for it, but in many cases, background noises can be effectively masked by your voice. However, the ongoing ambient noise becomes much more apparent during the pauses between words and sentences.
A noise gate can make a big difference when recording within a less than optimal environments. tools that cut out the audio signal when the sound level drops below a user-defined level. Noise gates are hardware or software-based audio processing applications that function by inserting silence in the spaces between phrases and during pauses when the audio level drops below a user defined threshold level. Narrators can use gates to reduce the impact of background sounds and noise within their recording space.
Hardware based noise gates are a great addition to any recording setup. Most recording software also includes software-based noise gates that you can apply to a noisy file after recording. These tools are relatively easy to operate, and can really make a difference in the quality of your final voiceover narration file.
You can also use software-based noise reduction functions that analyse the characteristics of the ongoing noises present within the recording, and apply selective processing to diminish these noises. These noise reduction functions are available as plug-ins or as part of the audio recording and editing software package.