Peak Volume
Damian Moore, Last updated: 15 October 2026
Peak volume refers to the point in an audio file which has the highest signal strength. It is a key factor in sound recording and reproduction. It isn’t representative of overall loudness because it might only last for a millisecond. If it is too high though it can indicate that the signal is being clipped and distortion is being introduced, reducing the listening experience. This headroom is also needed to ensure files are successfully encoded.
Peak volume needs to be high enough to allow for hearing enough dynamic range but it has to be measured in combination with LUFS (loudness). It can be a balancing act to meet standards in both and sometimes you’ll need to use dynamic range compression to get there.
Music, television, filmmaking, web content all have varying guidelines and best practices to be aware of. If you do nothing else, the main requirement is just make sure the peak is a little bit below 0dB. Software can bring the peaks down but if it was already at/above 0dB then the damage has already been done so try to make sure there aren’t peaks at the point of recording from the microphone.
Apple is the most influential body involved in the setting of podcast standards and they recommend that “true-peak value doesn’t exceed -1 dB FS”. Our check measures sample peak and fails if it goes above -1 dBFS. True peak can sit slightly higher than sample peak, so leave a little extra headroom.
Sample peak vs true peak
Our peak check reports sample peak — the loudest individual sample stored in the file. True peak is the level the waveform can briefly reach between samples once it’s reconstructed for playback, measured by oversampling. These inter-sample peaks can exceed what the stored samples show, so a file that just clears -1 dBFS in Audio Audit can still overshoot slightly on playback or once it’s re-encoded to AAC or MP3. Peak also needs to be judged alongside loudness (LUFS).
Fixing peaks with Audio Audit
Audio enhancement includes volume normalisation, which brings the whole episode to a target loudness with a single, constant gain change and then applies a true-peak safety limiter (-1 dBTP on the Podcast preset). The limiter only catches the occasional stray peak — it’s a backstop, not a levelling tool, and does nothing when nothing exceeds the ceiling. If your speech has lots of uneven peaks, the compression stage evens out the gap between loud and quiet speech before normalisation. Neither can repair audio that was clipped when it was recorded, so get your levels right at the microphone. See Enhancing audio for the options.
The peak check is Required at -1 dBFS in all the built-in standards (Podcast, AES speech and EBU R128). If you need a different limit, you can change it in a custom standard.
Header photo courtesy of @chairulfajar_
