Ever wondered what that tiny hole next to your iPhone's camera lens is for? Perhaps you never noticed it until you read the title of this article.

The tiny black speck has been a feature of Apple's smartphones ever since the iPhone 5, and most people never give it a second thought.

But it actually serves a very important purpose - particularly if you like to use your phone to record a lot of video.

The hole is actually a microphone - one of three on the body of the device. Another is hidden under the speaker grill on the front of the phone, and another sits on the bottom edge.

The idea is that the iPhone should be able to pick up all the sounds around you, no matter how you decide hold it.

Apple's marketing chief Phil Schiller laid out the benefits of the three microphone system during the launch of the iPhone 5, back in 2012.

"We now have not two but three microphones built into iPhone 5 - one on the bottom, one on the front, and another on the back," he said.

"This helps in many situations. You're doing a Facetime call, or you're creating a video, you've got the perfect placement for your microphones.

"We can use them for noise cancellation solutions, and we can use them for beam forming, which is important on voice recognition and applications like Siri."

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iPhone 8

If you don't think your iPhone's microphones are performing as well as they should be, you can test them yourself.

Just open Voice Memos, tap the record icon, speak into the microphone and then tap the play icon to play back the recording. You should be able to hear your voice clearly.

"If your voice sounds faint when you're using the speakerphone on a phone call, make sure that your iPhone receiver isn't blocked or covered," Apple says on its support page .

"If audio from video recordings sounds faint, or Siri can't hear you, make sure that the microphone near the iSight camera - on the top, back corner of your iPhone - and the receiver isn't blocked or covered."