Remove Microphone Hiss and Hum Online Free
Hiss and hum sound similar if you have never listened for the difference, but they are different problems. Hiss is broadband, spread across the spectrum, like the noise floor of cheap electronics. Hum is tonal: a low note, usually at 50 or 60 Hz together with its harmonics, that sits under the voice and never stops. A hum that sounds like a repeating machine loop is often a ground loop between devices.
Fix the source first
Before any software: hum that appears suddenly usually comes from hardware, not from the room. Try a different USB port or a different power outlet, move the microphone cable away from power cables, and if you are recording a laptop, unplug its charger and run on battery for a test take. Hiss, on the other hand, is mostly the preamp and the room, so the fixes are different: lower gain, record closer to the source, and treat reflections.
What remains after that is where denoising software earns its keep.
The test: two models on one hummy recording
The clip below is 28 seconds of speech recorded with a strong hum, the kind that sounds like a loop of machine noise under the voice. We ran two free denoisers over it: Fullband, the model behind this site, and RNNoise, the open source library from Mozilla that ships inside many VoIP and streaming applications. Both received the identical file and worked at the native 48 kHz sample rate. Nothing was trimmed or post-processed.
Listen in this order:
1. Original, with hum
2. Fullband result
3. RNNoise result
What to compare: how much of the low hum disappears, how the voice keeps its natural tone and level, and whether anything new shows up in place of the noise. RNNoise is remarkable for its size and its decades of deployment. Fullband is a full-band model that runs on a server, which gives it more room to work on the low end of the spectrum.
We are not printing a ranking. This is one voice, one hum, one room. The players above are the comparison.
Remove microphone hum and hiss on your own file
Every recording hums a little differently, so the only useful test is on your material. Upload the file to Fullband, listen to the result, and keep it if it passes. New accounts start with 50 free tokens, which covers several files.
FAQ
What is the difference between microphone hiss and hum?
Hiss is broadband noise, spread across many frequencies, like the sound of a poorly amplified room. Hum is tonal, usually at 50 or 60 Hz plus its harmonics, and it often comes from a ground loop or mains interference. The two sound different and respond to different fixes.
Can you remove microphone hum online for free?
Yes. Fullband processes hum and hiss in the browser on uploaded files, and new accounts start with free tokens. Some classic open source tools, like RNNoise, also remove hum on your own machine for free.
Is it better to fix the hum at the source?
Usually. A ground loop or a noisy power supply is best fixed with hardware: balanced cables, a ground lift, or a different USB port. Software removes what is left after that, but it cannot rebuild a clean recording that never happened.
Will noise removal affect my voice?
It depends on the model and how hard it is pushed. A model that removes too much tends to dull the voice or add a watery wobble. Compare the players in this article: the goal is hum gone and the speaker still natural.
Fullband is our product and is included with disclosure. RNNoise was run from its official source on the same input file. Sample rate and processing notes are kept in the Fullband engineering log.