Remove hum and clean up voice recordings on your Mac
By Himanshu Ranjan · Updated 8 November 2026
To clean up a recording on a Mac, select the audio file in Finder, such as a podcast episode, interview or voice memo, hold the right Option (⌥) key and choose Clean › Remove background hum to notch out 50 and 60 Hz hum, or Clean › Clean up voice to cut rumble, reduce noise and gently compress speech. Nothing is uploaded.
How to do it with FileDial
- Select the recording, such as an interview or voice memo, in Finder.
- Hold right ⌥ to open the dial.
- Choose Clean › Remove background hum for an electrical buzz, or Clean › Clean up voice for general speech cleanup.
- To tighten long pauses, run Clean › Remove silences… on the result.
- Compare before and after on the result card, and use Undo if needed.
Your original file stays untouched. The result is saved beside it, and every result has Undo.
Which option to pick
| Tool | Use it when |
|---|---|
| Remove background humClean | You hear a steady electrical buzz in a recording. Notches out 50 and 60 Hz mains hum. |
| Clean up voiceClean | Speech sounds muddy, rumbly or noisy. Cuts rumble, reduces noise and gently compresses the voice. |
| Remove silences…Clean | A recording has long pauses you want gone. Saves a new copy beside the original. |
Hum, rumble and noise are different problems
Mains hum is the low, steady buzz picked up from the electrical supply, often through a ground loop, an unbalanced cable or a laptop on its charger. It sits at the mains frequency: 50 Hz in most of Europe, Asia, Africa and Australia, and 60 Hz in North America and some other countries, with weaker copies at multiples of that frequency. Because the buzz lives at known frequencies, a notch filter can remove a very narrow slice of sound there while leaving the voice around it largely intact.
Rumble is lower still: traffic, air conditioning, footsteps or handling noise on a microphone stand. It carries little useful speech information, so cutting it cleans up a recording and saves headroom for the voice. Broadband noise, such as hiss from a cheap microphone or a fan, is spread across many frequencies and can only be reduced, not removed, without harming the voice. That is why gentle reduction usually sounds better than aggressive settings.
Light compression then evens out the gap between loud and quiet words, which makes speech easier to follow on phone speakers and in noisy places. Removing long silences is a separate edit: it shortens the recording rather than changing how it sounds.
- Steady buzz at one pitch: try Remove background hum.
- Muddy, roomy or hissy speech: try Clean up voice.
- Long gaps between answers: try Remove silences…
Why not upload recordings to an online noise remover
Recordings that need cleanup are rarely public yet. They are interviews with sources, customer calls, lectures, depositions, therapy-style conversations or family recordings, and many contain names, phone numbers or other personal details spoken aloud. Sending them to a free web tool puts that content on a server you cannot inspect.
The FBI Denver Field Office warned on 7 March 2025 that free online document converter tools are increasingly used to spread malware. The conversions work, but returned files can carry malware leading to ransomware, and the sites can scrape personal data such as identity numbers, banking and crypto details, emails and passwords. That warning was about document converters; the same logic is a good reason to keep recordings off file-processing websites.
FileDial processes recordings on your Mac. Files are never uploaded and every tool works with Wi-Fi off.
Other ways to do it on a Mac
GarageBand is free on the Mac and includes EQ and noise-gate controls, which can tame rumble and quiet the gaps between phrases if you are willing to tune them by ear. Video editors with audio tools can do similar work inside a project. For a single file you are already editing, those are reasonable options.
FileDial is quicker when the problem is specific and repeated: the same hum across a batch of interviews, or a set of voice memos that all need the same cleanup. One gesture from Finder applies a named fix, the result is saved as a new file, the result card shows what changed, and Undo is always available. The same tools also work on a video's soundtrack, such as a filmed interview or screen recording.
Questions
Should I choose 50 Hz or 60 Hz?
You don't need to choose. Clean › Remove background hum notches out both 50 and 60 Hz mains hum, which covers the electricity supply frequency in every region.
Can I use these tools on a video?
Yes. Remove background hum, Clean up voice and Remove silences… work on audio files and also on a video's soundtrack, so a filmed interview or screen recording can be cleaned the same way.
Can Clean up voice remove all background noise?
It cuts rumble, reduces noise and gently compresses the voice. Reducing noise is not the same as removing it entirely, so a very noisy recording will improve but may not sound like it was made in a studio.
Are my recordings sent to a server for processing?
No. Every FileDial tool runs on your Mac, files are never uploaded, and all tools work with Wi-Fi off. The only things that go online are a licence check and optional anonymous usage counts, which you can switch off in Settings › Privacy.
Can I process several recordings in one go?
Yes. Select all the files in Finder, hold right ⌥ and pick the tool once. FileDial runs it on each file, and recipes can chain tools, for example Remove background hum followed by Clean up voice.