LOL ok so the hiss is from choke or coil whine. I've have A LOT of electrics do it and never has any issues. It's completely normal. I had a nvidia gtx 285 that was insanely loud. It went away after hard use. If u wanna test out your device. Load up a game and leave it running and see what happens after that.
On a side note the video card I had I could reduce the whine my limiting the refresh rate to the sam as the monitor which was 60. About a month or so of use it went away. I doubt it would take the phone that long. I still have that car in use today and it's 7 years old. 5 of those years was 24/7 use.
Are you seriously comparing a video card to a phone? I have been a Silent PC builder for years and the video card fan and mechanical hard drives are two of the worst offenders for PC noise. Small fans running at high speed are hard to dampen the sound. SSD's took care of the mechanical HD.
There is no fan in the phone so I would not expect noise especially for a device that is made to go by your ear or in close proximity to your face.
A computer is typically a few feet away if on top of your desk or in a lot of cars under the desk. Foam, insulation, high end case and high end fans or liquid cooling can be used to make a Silent PC, even a high end gaming rig, but none of that would work with the iPhone.
I don't have my 7 Plus yet but with the noise issue, apparently no Sapphire glass on the camera lens or home button has me rethinking about just staying with my 6s Plus until the 10th anniversary iPhone next year when they hopefully make substantial physical design changes to reduce the in hand size and improve the screen resolution.
All jokes aside with the Note 7 and Android, it is physically a beautiful phone to hold and the camera and screen are excellent. A Note 7 running iOS would be a perfect phone.
I was a long time Android slappy until Apple came out with the larger 6 Plus and I found how easy and great iOS is for me and how I use my phone. The 6s Plus was a nice upgrade as would be the 7 Plus but just a touch disappointed with the early reviews on the hardware side.
My only issue with the 6s Plus is it is physically much larger than it needs to be. Screen is very good until you put it side by side with a Samsung screen.
iOS 10 is a great software upgrade and really runs excellent on the 6s Plus and makes it feel fresh again.