Some Apple iPhone 7 users are reporting a hissing noise coming from their phones. The noise was first noticed by 512 Pixel’s Stephen Hackett, who posted the sound on YouTube. Since then others, including TechCrunch’s Darrell Etherington, have said that they too are hearing the sound. Hackett says that the sound was coming from the back of the phone, possibly from the CPU and added that it seemed to get worse if the phone’s CPU was under heavy load. Hackett has since been in touch with AppleCare and says that the company will replace the phone.
Apple hasn’t commented on the issue yet and no one has found a concrete reason as to why such a noise would occur. This is especially troubling considering that there aren’t many moving parts in the smartphone (such as a fan) that would make such a hissing sound.
https://twitter.com/etherington/status/777184006735556608
It is possible that the noise could be coming from the new A10 Fusion chip, as it seems to go worse if the SoC is put under heavy load. However, the guys over at Apple Insider speculate that the noise may have something to do with the RF transmitter or there is some interference with the speaker. Engadget believes that the noise could be a coil whine or similar electromagnetic effect. The website also tested its device using 3DMark “Ice Storm Extreme,” which is designed to put strain on the processor. However, they did not hear any hissing sound. It is possible that this could be an issue related to manufacturing, rather than a design flaw.