Apple has confirmed the complaint of some iPhone 8 and iPhone Plus owners regarding the disruptive sound in their earpieces during phone calls and said it was working toward resolving the issue.

Users have reported online, including on Reddit and Apple's forum, that the earpieces make a "crackling" or "static" sound that "disrupts the audio" when they make calls.

"We are aware of the issue which is affecting customers in a small number of cases. Our team is at work on a fix, which will be included in an upcoming software release," Apple said to the Verge in a statement.

The problem seems to be with the device's earphone and occurs during regular calls and Facetime calls.

It is not yet clear how many iPhones have been affected by the issue, which is happening across carriers and is taking place globally.

“I returned my iPhone 8 Plus 64GB Space Grey yesterday after speaking with tech support for over 2 hours. The replacement phone I got yesterday is doing the same thing. Cracking noises during calls. If this is not resolved stat, I will be returning for a refund and going back to my iPhone 7,” a user who goes by the name j_m01 posted on the Reddit thread about the issue.

“It is a high-pitched crackle like an audio pop that happens in the earpiece top speaker intermittently during calls. Some calls are fine and others crackle. It is not audible on earphones or on speakerphone, only through the earpiece. The caller on the other end doesn’t hear it," a user complained on Apple’s forum.

The user also said the problem may be software related.

"I don’t know whether this is hardware or software related, but one thing that made me think it’s software related is that if you switch on to speakerphone for a few seconds then back to earpiece, the crackles resolve for the duration of the rest of the call. If this was a hardware issue with the earpiece, doing this shouldn’t make a difference,” the user said.

Here’s a disrupted audio recorded on one such call.

What’s reassuring though is that the disruption does not take place during every call, and it might just be a software issue, which can be resolved by a software update. The company recently issued the iOS 11.0.1 update for correcting some bug fixes with the iOS 11.

The issue can be bypassed by using headphones or the speaker phone. You can also try things like resting the device or making voice over internet calls, using apps such as Viber. Though, none of these seem to be a credible solution.

This is the second time the tech giant has promised a fix for one of the new devices it shipped this month. A software glitch with the Apple Watch Series 3 caused the watch to connect to unauthenticated Wi-Fi networks instead of handing off to LTE.