Ultrasonic cleaning with kirmuss and loss of high frequency details.

I have cleaned thousands of records with my US setup. What I hear is a reduction in high frequency content - but it is the hf NOISE which is gone. Like the hf tizz which is characteristic of low quality capacitors or resistors.

The US cleaning thread has lots of such information, like the test which I did to detect US damage. I didn't find any.

Hemoncdoc, I always use ear protection near an US machine.

@lewm

My Elmasonic is specced at < 105dB at 1 meter, with the cover on; that’s one hell of a lot of sound power in an enclosed space. And of course the cover is not on when cleaning vinyl.

It would depend on the middle ears’ being able to transmit US frequencies, something of which Tim Paravincini seems quite sure - he designs for it. I see no reason to doubt it - whether there are hair cells to vibrate at that frequency or not (and so initiate the sensation of hearing), the energy may still be there in the semi-circular canals, breaking hair cells and permanently damaging hearing.

So I use protection. Just in case.

@lewm 

105 dB at US frequencies. It's only a bit noisy at the 80 KHz setting, while irritating at 37. Still, nowhere near 105.