AudioBufferSourceNode has no input and exactly one output. The number of channels in the output corresponds to the number of channels of the AudioBuffer that is set to the AudioBufferSourceNode.buffer property. If there is no buffer set—that is, if the attribute's value is NULL—the output contains one channel consisting of silence. An AudioBufferSourceNode can only be played once; that is, only one call to AudioBufferSourceNode.start() is allowed. If the sound needs to be played again, another AudioBufferSourceNode has to be created. Those nodes are cheap to create, and AudioBuffers can be reused across plays. It is often said that AudioBufferSourceNodes have to be used in a "fire and forget" fashion: once it has been started, all references to the node can be dropped, and it will be garbage-collected automatically.