Noise Floor

The inherent noise of a recording medium, a noise floor typically sounds like hiss and differs with the makeup of different types and qualities of tape and film.

For example, a consumer grade cassette tape has a higher noise floor than a professional 1/4” tape, and a high quality digital recording has a lower noise floor than an analog magnetic tape recording.

Optical soundtracks tend to have higher noise floors than magnetic tape. In general, with older material the noise floor can be very noticeable. Noise reduction processes such as Dolby® A, Dolby SR, and DBX are designed to reduce the noise floor while still maintaining the intended program level.

The noise floor, the sound in this clip resembling "shhhhhh," is very high compared to the level of program.

This is the same sound clip but now the noise floor is modulating between the lines of dialog.