I don't know about high frequency but my A/C compressor makes the clicking and tapping noise when it turns off and on. I wouldn't describe the noise as high frequency, more like a normal sound a clutch would make when it engages and disengages. I've owned many (4) GM cars in the past and I would say their compressors weren't as loud as the Volvo's, but you could still hear them if you were listening for them.

Hope this helps

Scott