The start() method of the MessagePort interface starts the sending of messages queued on the port. This method is only needed when using EventTarget.addEventListener; it is implied when using MessageChannel.onmessage.
The most simple example just starts the audio buffer playing from the beginning — you don't need to specify any parameters in this case:
The MediaRecorder.start() method (part of the MediaRecorder API) is used to start capturing media into a Blob.
The following example shows basic usage of an AudioContext to create an oscillator node. For an applied example, check out our Violent Theremin demo (see app.js for relevant code).