I've actually noticed similar effects with almost every AP I've ever used, including the Cisco Aironet 1252's that used to be mounted right outside my college dorm room.
It makes little high pitched capacitor/inductor whine noises with little pulses.
I've actually not heard it much from my R600 or R700, but my Netgear consumer AP (R7000) made really loud whining noises too on 5GHz.
Perhaps it's worth going to observe the noise and comparing multiple 7352's side by side to see if there's more noise coming from one or the other? I've went on a trip with someone who complained that the smoke alarm in the room was making a "beeping" noise, but I couldn't hear a thing. Some people are more sensitive to high-pitched noises than others.
