The silent chunk is a way to represent silence using a small number of bytes.
A silent chunk in a Wave file has the following structure.
|Byte sequence description||Length in bytes||Starts at byte in the chunk||Value|
|chunk ID||4||0x00||The ASCII character string "slnt"|
|size||4||0x04||The value 4. This value is the size of the silent chunk (number of bytes) less 8 (less the "chunk ID" and the "size")|
|data||4||0x08||The number of samples through which playback should be silent|
Playback will halt at the last sample value, which could be silence, or could be anything else. To avoid pops and clicks, the preceding data chunk should actually end in silence (see Format chunk (of a Wave file) for information on how silence is represented).
Wave file format