Noise Floor
Damian Moore, Last updated: 15 October 2026
In audio engineering, the “noise floor” refers to the level of unwanted background noise (e.g. hiss or hum) present in an audio signal or system. It represents the cumulative sound created by electronic components, environmental interference, or any inherent system noise when no audio signal is present. This noise is typically a combination of various factors, including electrical interference, circuit noise, and ambient environmental sounds.
A lower noise floor is desirable in audio equipment as it allows the intended audio signals to stand out, ensuring a cleaner, higher-quality audio output. Audio engineers often work to minimize the noise floor through various techniques, such as using high-quality components (mics, mixing consoles, sound cards, analogue recording mediums and electronics), proper gain staging, and noise reduction technologies.
We recommend the noise floor should be below -60dB.
–60dB is really a maximum but different types of noise are more noticeable/acceptable than others. A low frequency rumble might be unnoticeable at –60dB but a high-frequency or hissy one would be. –96dB below peak is ideal as it’s imperceptible to most humans.
Hiss noise is particularly detectable when listening on headphones or close up to speakers in quiet spaces.
In Audio Audit’s built-in standards the noise floor check is Informational with a limit of –60dB. If your show needs a stricter or looser limit, or you’d rather make it Required, you can change it in a custom standard.
Noise floor vs unwanted noises
The noise floor is the constant background that sits under the whole recording — hiss, hum, fan or air conditioning noise, the sound of the room. Short, one-off sounds such as coughs, sneezes or a pet in the background are a different problem, and Audio Audit has a separate Unwanted noises check for them. Those show up as amber markers on the report’s waveform and are tagged on the matching phrases in the transcript, so you can jump straight to each one. You can read more about it in our unwanted noise detection announcement.
Solutions
If you are trying to get rid of noise the obvious solution might be to buy better equipment but there are other things that may be the problem. First you should investigate sound-proofing, pre-amps, audio interfaces/drivers, power cables and other electronic devices. Once you are convinced you are getting as good a signal out of your equipment as possible, here are some fixes you can perform in post (digital audio workstation — DAW).
1. High pass filter
This is only applicable if your noise is very low frequency. You’ll want to apply this to your microphone channels as early as possible before you mix. You can make a HPF tailored to the voice and it will work across the whole of the track — not just in the gaps.
2. Expander
An expander is a bit like a compressor but lowers the quiet parts. You could also use a noise gate but an expander can be more subtle.
3. Noise reduction software
This should be a last resort but there are lots of different ones to choose from and AI is improving the quality all the time. Be sure to not be too aggressive with them though or you’ll start hearing artifacts. For heavier or more surgical repair work, a dedicated tool such as iZotope RX is an option — we compare it with Audio Audit in our iZotope RX comparison.
Reducing noise with Audio Audit
Audio Audit can also enhance your audio, and noise reduction is one of the options. Rather than assuming what your noise sounds like, it builds a noise profile from your own recording by measuring its quietest moments. It then applies a gentle broadband smoothing pass and spectral noise reduction, which subtracts that measured profile frequency-by-frequency while leaving speech intact. When there is audible room tone between phrases, a soft speech gate gently lowers the level in the gaps rather than hard-muting them, so pauses still sound natural.
Reduction is capped at 12dB, deliberately below the point where the swirly “musical noise” artefacts appear. You can pick Auto (the default, guided by your measured room tone), Light, Medium or Strong. If your recording is already gated (silence between phrases from a voice-activated recorder or software), Audio Audit detects this and skips the steps that rely on natural room tone.
It works best on the voice track before music is mixed in, as music can mask the difference between noise and content. And if your recording is noisier than 12dB of reduction can fix, the better fix is still at the source — a quieter room or a closer microphone. See Enhancing audio in our user guide for the full details.
Header photo courtesy of Denis Degioanni
