Hiss, Hum, Wind or Echo? How to Identify Background Noise and Fix Each Type

Most people describe every unwanted sound in a recording the same way: "there's background noise." But a steady fan, a 50 Hz electrical buzz, a gust of wind and a neighbour's conversation are very different problems. A fix that removes one can do nothing for another, or make the voice sound worse.

Spending thirty seconds identifying what you are hearing saves a lot of trial and error. Put on headphones, find a moment in the recording where nobody is talking, and listen.

1. Hiss: a steady "shhh"

What it sounds like: a soft, constant, high-pitched rush, like a radio between stations, that never changes.

Where it comes from: cheap or built-in microphones, gain turned up too high, long cables, older recorders, or a quiet voice that was boosted a lot afterwards.

How to fix it: hiss is the easiest noise to remove because it is constant. Classic noise reduction (Audacity's Noise Reduction, the Reduce Noise option in Premiere Pro's Essential Sound panel, CapCut's Reduce noise switch) learns what the hiss sounds like from a quiet section and subtracts it. Start with gentle settings: pushing too far makes the voice sound watery or "underwater."

Prevent it next time: get the microphone closer to your mouth so you can record at a lower gain.

2. Hum and buzz: a low, musical drone

What it sounds like: a low tone that seems to have a pitch, sometimes with a buzzy edge. It is often at 50 Hz (Europe, most of Asia, Africa, Australia) or 60 Hz (the Americas, parts of Japan), plus its harmonics.

Where it comes from: electrical interference, ground loops between a laptop and an audio interface, unshielded cables, fluorescent or dimmer-controlled lights, or a fridge or air conditioner close to the mic.

How to fix it: use a dedicated hum remover rather than general noise reduction. Premiere Pro has DeHum, DaVinci Resolve's Fairlight has a Hum Removal effect, and Audacity users can apply a notch filter at the hum frequency. If you do not know whether it is 50 or 60 Hz, try both and keep the one that works.

Prevent it next time: unplug the laptop charger while recording (a very common cause), keep audio cables away from power cables, and move away from the fridge.

3. Wind: low thumps and rumble

What it sounds like: irregular low booms, rumbles and "pops" that come and go with the gusts. On a phone it can sound like the mic is being hit.

Where it comes from: moving air hitting the microphone capsule directly. Outdoor phone videos are the classic case.

How to fix it: wind is hard for traditional tools because it keeps changing, so a noise profile taken from one second does not match the next. A high-pass filter (cutting everything below about 80 to 120 Hz) removes some of the rumble without touching the voice much. For the rest, AI noise removal does much better, because it is trained to recognise speech and keep only that, rather than relying on a noise sample.

Prevent it next time: shield the mic with your body or a hand, face away from the wind, or use a foam or furry windscreen on an external mic.

4. Traffic, crowds and chatter: changing noise

What it sounds like: cars passing, a café full of people, kids playing, a TV in another room. The noise changes all the time and some of it is human voices.

Where it comes from: recording anywhere that is not a quiet room.

How to fix it: this is where classic noise reduction struggles most. Background voices are speech too, so a filter cannot simply separate "voice" from "noise" by frequency. Speech-trained AI models handle it better: they focus on the closest, most dominant voice and suppress everything else, including distant chatter. Results depend on how loud the background is compared to the main speaker, so always listen to a preview before committing.

Prevent it next time: get closer to the person speaking. Halving the distance between mouth and mic makes the voice noticeably louder relative to the room, and that does more than any software.

5. Room echo and reverb: the "empty room" sound

What it sounds like: the voice sounds distant, hollow or like it is in a bathroom. Words seem to ring on after they end.

Where it comes from: hard, bare surfaces (walls, floors, windows, tiles) bouncing the sound back into the mic. Common in new apartments, offices, kitchens and classrooms.

How to fix it: echo is technically a different problem from noise: it is the speaker's own voice, delayed. Noise removal tools mainly target noise, though some reduce a little reverb as a side effect. Dedicated "de-reverb" tools exist (DaVinci Resolve Studio's Voice Isolation and dialogue tools, Adobe's Enhance Speech), but heavy echo is very hard to remove fully after the fact.

Prevent it next time: this one is much easier to prevent than to fix. Record in a room with soft furnishings (a bedroom with a bed, curtains and a rug is ideal), stay away from bare walls, and keep the mic close.

6. Clicks, pops and mouth noise

What it sounds like: short, sharp transients: plosive "p" and "b" pops, lip smacks, keyboard clicks, a chair creaking.

How to fix it: these are short events, so noise reduction is the wrong tool. Use a de-click or de-plosive effect, or simply cut or lower the individual sound in your editor. A pop filter, or speaking slightly across the mic instead of straight into it, prevents plosives.

Quick reference

Noise	Sounds like	Best fix
Hiss	Constant "shhh"	Classic noise reduction, gentle settings
Hum / buzz	Low tone with a pitch	DeHum or a notch filter at 50 / 60 Hz
Wind	Irregular low thumps	High-pass filter, then AI noise removal
Traffic, crowds, chatter	Changing, includes voices	AI noise removal
Echo / reverb	Hollow, distant voice	Prevent it; de-reverb tools help a little
Clicks and pops	Short, sharp sounds	De-click, or cut them by hand

What to do when a recording has several kinds at once

Real recordings usually mix several problems: an interview in a café has chatter, clatter and some room echo; a phone video on a street has wind and traffic. Fix them in this order:

1. Remove hum first, with a dedicated hum remover, since it is the most predictable.
2. Run noise removal for everything that remains (hiss, wind, traffic, chatter).
3. Deal with individual clicks and pops by hand.
4. Only then add EQ and compression, so you are not boosting noise you are about to remove.

If your editor's built-in tools leave too much behind, that is usually because the noise keeps changing. Our step-by-step guides show what each app can do: CapCut, Premiere Pro, DaVinci Resolve and Audacity. For the noise they cannot handle, an AI noise remover such as Denoiso keeps the voice and drops the rest, and lets you hear a free preview first.