How to Remove Background Noise in iMovie

Select your clip, enable Reduce background noise, and adjust the amount until the unwanted sound is lower without making the voice sound unnatural.

If the recording is still noisy, you can export the video and try cleaning the finished file separately.

Apple includes background noise reduction directly in iMovie for Mac.

To use it:

1. 1

   Select the clip. Select the video or audio clip in the timeline.

2. 2

   Open noise reduction. Click the Noise Reduction and Equalizer button above the viewer.

3. 3

   Enable the control. Enable Reduce background noise.

4. 4

   Adjust the amount. Adjust the slider to control how much noise reduction is applied.

5. 5

   Compare the result. Play the clip and compare the result.

The slider runs from 0% to 100%.

Do not automatically push it to 100%. More noise reduction is not always better. If the voice starts sounding thin, metallic or unnatural, reduce the setting until you find a better balance.

iMovie can help with unwanted sound underneath speech, especially when the noise is relatively consistent.

Examples include:

• fan noise;
• air conditioner or HVAC noise;
• room noise;
• hiss;
• electrical hum;
• distant traffic.

Results depend heavily on the original recording.

A clear voice over steady background noise is generally easier to clean than speech mixed with changing sounds such as wind, keyboard clicks, music, crowds or other voices.

If you know what type of noise you have, these guides may help:

• remove fan noise from audio
• remove air conditioner noise from audio
• remove room noise from audio
• remove hiss from audio
• remove hum from audio
• remove traffic noise from audio
• remove wind noise from video

If increasing Reduce background noise starts damaging the voice while the unwanted sound is still audible, the recording may have reached the practical limit of that particular cleanup method.

Instead of repeatedly applying stronger processing, compare the original recording with another noise-removal tool.

With Noisero:

1. 1

   Export your video from iMovie. Export your video from iMovie.

2. 2

   Upload the video to Noisero. Upload the video to Noisero.

3. 3

   Hear a short cleaned preview. Hear a short cleaned preview.

4. 4

   Compare it with the original. Compare it with the original.

5. 5

   Process the full file. Process the full file only if the preview sounds better.

No signup is required to hear the preview.

Noisero cleans the audio track while leaving the video itself unchanged.

iMovie on iPhone has audio controls for things such as volume, muting and background/foreground audio, but it does not provide the same dedicated Reduce background noise control documented for iMovie on Mac.

If you already edited a noisy video in iMovie on iPhone, export the video first and clean the resulting file separately.

Upload the exported video to Noisero and listen to the cleaned preview before processing the whole file.

This is especially useful if the video contains speech recorded with:

• a noisy laptop or room fan;
• air conditioning;
• traffic;
• microphone hiss;
• wind;
• keyboard noise.

Background noise and speech are not completely separate signals.

When unwanted sound overlaps with a person's voice, aggressive noise reduction can start removing parts of the voice too.

That can make speech sound:

• thin;
• metallic;
• muffled;
• watery;
• robotic.

The goal is usually not absolute silence between every word. It is to reduce the distracting sound while keeping the speaker natural and easy to understand.

Noise reduction cannot completely repair every bad recording.

Clipping and microphone distortion happen when the original signal was captured incorrectly. If part of the voice was already distorted or lost during recording, noise reduction cannot perfectly recreate it.

Likewise, if loud music, another speaker or strong wind completely covers a word, there may not be enough clean speech information left to recover it.

If possible, perform noise reduction on the original recording before applying several other audio effects.

Running an already heavily processed file through more noise reduction can create additional artifacts.

If you already tried aggressive settings in iMovie, go back to the original clip before comparing it with Noisero.

For a broader workflow, see how to remove background noise from video.

A cleaner recording requires less processing later.

When possible:

• move the microphone closer to the speaker;
• move away from fans and air conditioners;
• avoid recording next to an open window or busy road;
• use a windscreen outdoors;
• keep recording levels low enough to avoid clipping;
• record a short test before an important video.

Noise reduction is useful, but preserving a clear voice in the original recording gives every cleanup tool more to work with.