I will edit your audio to anything you want with a free preview

ie. We cannot remove variable background noise like close cars, people talking, nearby traffic, etc. in a ongoing dialogue. We cannot remove artifacts from compression like MP3 encoding.

Lossless audio that is uncompressed (not reduced in file size) like WAV, AIFF, FLAC. Compressed audio is anything like MP3, MP4, OGG, AAC where the audio is degraded in order to significantly reduce the file size.

Depending on your video codec (and file size) we can extract the audio and denoise that. We will not re-encode the audio to the video so no video is delivered back, only audio.

Gain staging is the process of ensuring that the audio is set to an optimal level for the following processor in the chain to minimize noise and distortion. Doing this will result in the best possible signal to noise ratio.

A mono or stereo file. The edit will be applied the same way for both sides. A multitrack audio file (more then 2 sides) can require multiple passes.

Anything that is added after the actual recording, altering the signal and thus it's noise floor. Some are: Delay effects, Reverb, Signal Compression (this is not the same as file compression), Phaser, chorus and flanger effects.

Technically yes, but in reality the file has lost much of its original data, often altering and modulating the natural noise floor. Audio compression (like with MP3) introduces additional artifacts that become especially noticeable if you apply a denoise profile.