outputLatency read-only property of the
AudioContext Interface provides an estimation of the output latency of the current audio context.
This is the time, in seconds, between the browser requesting the host system to play a buffer and the time at which the first sample in the buffer is actually processed by the audio output device. It depends on the platform and the available hardware.
var latency = audioCtx.outputLatency;
A double representing the output latency in seconds.
const audioCtx = new AudioContext(); console.log(audioCtx.outputLatency);
|Web Audio API
The definition of 'outputLatency' in that specification.