I think I can tell the difference between coil whine and physical movement like the Taptic Engine or focus motor in the camera. In fact, while writing this reply, I am trying to put my ear to the back of the iPhone 16, right under the camera bump, an area which is the location of most chips, and I can hear some sounds, especially when I try to scroll or tap the screen at the same time.
Maybe not the best idea to tell them this might occur with most devices if you are extremely close to them (which is fine, physics are a thing).
There is some switching noise in most electronics if you listen carefully enough.
An Obsessive compulsive personality that goes looking for these issues by putting themselves in a situation where they try to hear the “problem” without understanding what’s happening and assuming there are defects is the real problem, because unless something is pretty wrong (e.g. M1 studio exhaust design causing resonance), it isn’t worth worrying about or even trying to find.
Coil whine can exist in actual power coils but for SMD components and high clock electronics it’s much more likely resonant frequencies and switching noise, such as with most current-gen SSDs performing heavy writes.
It’s the human behavior that should change here, because it’s not a healthy way to live. Nobody is putting their head against a laptop in use, and people aren’t using these in anechoic chambers, which Apple does during development and validation to test things from noise to signal strength etc.
This is an overly sensitive person compulsively trying to find a problem because they are compelled to, again see the extensive post history about everything from slight gaps in a phone frame and, the most unsurprising thing, a post about using a “special” iPhone case to block EMI. Let that one sink in for a minute, because you’re not going to get a good cell signal through something that doesn’t let EMI pass, and the exposure limits are very well studied, regulated, and tested both by Apple and third parties.
Can’t be a fun way to live. I really meant what I wrote to help, looking for problems will find them. Not knowing it exists is much better for people who are wired that way.
If you let it go unchecked forever it just gets worse and worse. I have had some experience with people who fell into that spiral.
Now, maybe the M4 air specifically does have something wrong, I haven’t tried one in person, but given the lack of many other reports as well as taking context into account I very much doubt it, and I certainly wouldn’t make such a bold claim that “coil whine is the new normal”.