iPhone 7 and 7 Plus Exhibiting 'Hissing' Noises Under Load for Some Users

After the iPhone 7 and iPhone 7 Plus began arriving to the first round of pre-order customers on Friday, a few users noticed what's become known as a "hissing" sound emanating from the back of the device, where the Apple logo is located. The first reports began on Friday, but the occurrence gained ground when 512 Pixels' Stephen Hackett tweeted about it, posting a video with the "terrible noises" produced by his iPhone clearly audible, which he determined to be caused by heavy performance at the time.

I just came back from the Apple Store.

They had no idea what it is and what could it be (not surprising as this phones just came out today), so they ordered a replacement phone for me /:

They could reproduce the issue easily. Also I noticed that when turning on the phone you can hear it very well, I guess because of the extra processing that is being done while booting the device.

Kind of disappointed they don't have a few in stock for cases like this, but on the other hand it sounds like an issue more common than 1 damaged phone. so I hope that if it is a faulty batch or something like that so the wait my pay off and by the time I get my replacement phone it will be fixed.

Since his tweet, more and more iPhone 7 users have come forward about the issue and corroborated Hackett's story. On the MacRumors forums, mentions of a "buzzing" and "static" sound coming from the back of the iPhone 7 and iPhone 7 Plus began on Friday afternoon. Specifically, forum member maxlind noted that the noise happened on his 128GB iPhone 7 Plus under load, without charging or restoring from an iCloud backup.

My new iPhone 7 Plus (128GB, Black) has an odd buzzing / static sound coming from it. Specifically, if I put my ear up to the back of the phone where the apple logo is, I can hear the battery or processor or something “working”… note the sound file attached.

Nope, not charging. I thought maybe at first it was just the phone overworking itself during an iCloud restore (it got pretty hot too)... but the noise is still there.

One Redditor who got his iPhone 7 Plus replaced at an Apple store noticed immediately that his new iPhone was making a similar sound, so the issue could potentially be affecting a large number of iPhone 7 and iPhone 7 Plus models due to the high-capacity performance abilities of the A10 chip. Since there are no actual moving components on the chip, it's still unclear what could be making the noise.

As pointed out by The Verge, the consensus of the noise's origin online is that it's caused by a phenomenon known as "coil noise."

What’s going on here? Potentially nothing major, and Apple declined to comment on this story. So we can’t say for sure what the cause is yet, nor how widespread it is — though to the latter point, it doesn’t seem to be affecting a large number of users.

The consensus around the web right now is that this is some form of “coil noise” or “coil whine” — the sort of sound a high powered processor or virtually any electronic part can make, especially when it’s not properly dampened. It can crop up when the chip is under heavy load, and you might be able to hear it on any recent phone if you put it under load and listen very closely. I can, for example, hear some high-pitched noises on my Galaxy S7 Edge if I hold it up to my ear in a quiet room.

Still, despite the problem slowly becoming infamous over the weekend, some sites tried to replicate the issue and failed. Using performance benchmark software 3D Mark "Ice Storm Extreme," Engadget ended up hearing "no hissing at all" on the 4.7-inch iPhone 7. As many users have theorized, the sound issue could "stem from a manufacturing issue instead of an inherent design quirk." Until Apple addresses the problem, that still leaves affected users to either deal with the noise, or attempt to get a replacement that could potentially face the same sound.