Gives each AudioParam a new attribute, automationRate that allows the user to select whether the AudioParam is either "a-rate" or "k-rate". Most but not all AudioParams allow changing the rate (as given in the spec). For example, BiquadFilterNode with default "a-rate" automation is very expensive to compute due to the complex relationship between the parameters and the filter coefficients. If this fast automation is not needed (the most typical case), the parameters can be set to "k-rate".
Docs: https://github.com/WebAudio/web-audio-api/issues/1269 https://github.com/WebAudio/web-audio-api/pull/1521