Control the Audio Preview

Want more control over audio previews? Adjust your preferences. The preview settings affect all aspects of audio previews, but have no impact on your renders . To access the audio controls, choose After Effects>Preferences>Previews (Edit>Preferences>Previews). The more you reduce audio overhead, the faster you can preview.

Duration. This setting controls how much audio is previewed when you invoke an audio only preview.

Sample Rate Higher sample rates are used for professional audio. With that said, you likely do not need to hear 48kHz of audio for a preview. A rate of 22kHz (or even 11kHz) should be more than adequate for preview purposes.

Sample Size After Effects supports 8-bit and 16-bit audio. While it is important to render all 16 bits, 8 bits is adequate for preview purposes.

Channels Do you have multiple speakers on your system, or are you using a single builtin speaker? In most cases, mono previews are adequate.