timed runs every approx 30 minutes. timed itself does not directly affect audio. each timed run results in multiple log lines in console.
Immediately after timed has started its run, you might or might not see multiple kernel calls affecting IOAudio. This is what causes the audio glitches. The audio system is being stopped and immediately restarted.
Turning off time and time zone synchronisation does not in itself stop the calls to timed but it does seem to have some effect on whether or not you hear any glitches.
I have also recently turned off ALL notifications and this seems to have had a beneficial effect. I still see the audio system being stopped and restarted occasionally but usually do not hear a glitch.
I realise this all extremely nebulous but it seems to just be like that. Nothing is definite here until Apple actually fixes this. It could also all be just in my mind