AudioFade
AudioFade[audio] returns audio in which the beginning and end of audio are faded.
AudioFade[audio, t] fades the first and last t seconds of audio.
AudioFade[audio, {t1, t2}] fades t1 seconds at the beginning and t2 seconds at the end.
Examples
Apply fade effect:
audio = ExampleData[{"Audio", "Bird"}];
AudioFade[audio, 0.5]Please visit the official Wolfram Language Reference for more details.