Under Input Data Source, click WAV File to display the following dialog:
File Name: Specifies the name of the WAV file to be used as input, or click … to select it.
Input Data Source/.WAV File: Indicates that the audio data is read from a WAV file.
Loop: If the simulation range is longer than the length of the audio data, this parameter allows the audio data to be played over again until the end of the simulation.
Show Icon: Changes the display of the block
to 
.