Descript's low-pass filter — also known as a "hi-cut" filter —is used to remove high-frequency audio from your media clips. This can be especially useful for reducing unwanted noise from electromagnetic interference (like a nearby cellphone), hiss, or other sharp sounds that may have been captured during recording.

The effect includes several presets, so you can experiment with different settings to achieve the best result for your project.

You can apply the effect from the Audio Effects section of the Layer panel.