On iPhone
- Open the file or video in Noise Reducer.
- Start with Balanced. Go up only if you still hear the fan.
- Compare with the original, then save.
On a computer with Audacity
- Select a few seconds where only the fan is audible.
- Open Effect, Noise Reduction and click Get Noise Profile.
- Select the whole recording and open Noise Reduction again.
- Start around 6 to 12 dB, preview, then apply.
Audacity's profile method works well for steady fans. Its manual says it is not suited to irregular noise such as traffic.
Avoid it next time
- Turn off fans and air conditioning while recording, even for a few minutes.
- Point the microphone away from the fan.
- Use the decibel meter to find the quietest spot in the room.
Questions and answers
Can you remove AC noise from a video?
Yes. Air conditioning is steady noise and Noise Reducer removes it well while keeping the picture untouched.
Why does my voice sound underwater after noise reduction?
The reduction is too strong for that recording. Lower the strength or use a speech model instead of a profile method.