Hi people,
So I know that there are lots of iPhones hissing like a rattlesnake but I wanted to give you guys my own experience with my iPhone 7 Plus 32GB.
I pre ordered my iPhone 7 Plus via an Apple Reseller in the Netherlands and had to wait since September 9th (!). Yesterday I could finally embrace my brand new iPhone 7 Plus 32GB. However, after reading through some topics about the hissing I put the phone close to my ear, and yes, I could hear the hiss...
I immediately went nuts since I hate having issues like these on my brand new phone. I contacted Apple and they said it's quite common for the phones to produce a sound. The sound can be described as sizzling/hissing/cracking noise which can only be heard if you hold the back of the phone close to your ears.
After the initial shock I decided to return the phone but Apple told me that I would likely get another one that has the same problem, so I decided to wait a couple of days. I wouldn't mind the hissing because a normal person doesn't hold the back of it's phone against his/her ear. But the problem is: the microphone picks up the noise.
I decided to call up some different people from Apple and was finally able to contact one of the engineers. He told me the noise produced by the chips are quite normal since they are so high-powered. But the microphone thing is not normal, he told me Apple is currently working on it and it might be patched. Since the microphone is too sensitive right now they COULD fix it by lowering microphone sensitivity, but don't quote me on this. I made some videos on iPhone 6S' and found the same noise, but not as loud as the iPhone 7 Plus. Apple told me almost
ALL iPhone 7's do HISS, however, most people are not able to hear it because of the high frequencies, but if you have sensitive ears like mine, you can definitely hear it. Some phones can also be louder than others but the margin is not that bigger. There are no phones that are DEAD SILENT, but there are phones most people can't hear hissing.
I wanted to share this information with others so maybe the 'omg what is this'-feeling would go away. I have planned an appointment with a geniusbar this Thursday and I'll make my final decision (keep or return) after that. I have made a nice summary below for people who're lazy to read
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Summary
Problem
- iPhone 7 Plus generates a hiss/crack/buzz sound which can be picked up by the microphone
Potential causes (after my research)
- Microphone is too sensitive (can be patched in future software updates)
- Processor is doing too much things at the same time that causes it too produce sound, this means it isn't designed properly (maybe throttling in future updates, but likely a hardware problem)
- Noise cancelling feature is set too high (can be patched in future software updates)
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I do believe that this is not that big of an issue since so many iPhones have it, the phones are working fine but the noise is just there because of the way the A10 Fusion chip is designed.
I hope you liked this topic, leave your comments down below. I will update this topic on Thursday after I visited the 'Genius'bar. Apple already declined to swap it out for a new one because I bought it through a reseller which doesn't have stock for the next couple weeks. So it's either let it hiss or two weeks without a smartphone (suicide).
. There's also a short version written below the larger paragraphs, for lazy people 
