Smartphones have become an indispensable part of our lives. Especially, iPhone has much craze among the people due to its stunning look, incredible features, and design. Usually, people use the smartphones to store an immense quantity of personal information, from our private conversations to our photos and much more. Despite the fact that millions own an iPhone, many are oblivious of some of the most amazing features hidden away in this little device. Have you ever noticed a tiny hole on the backside of the iPhone i.e in between the flash light source and the camera? Do you know,what purpose does this tiny hole serves?
This tiny hole is generally on the rear side of the iPhone. But for some phones it is on the front side,adjacent to the front camera. This tiny hole is known as “Noise Cancelling Microphone“. Let us know in detail about this microphone.
You may call from your iPhone when you are in a fully noisy area. But the receiving end doesn’t listen to any noise. This is because of the special audio system present in your iPhone. This is known “Noice Cancellation System”. Here are the details about this system. There are three microphones on an iPhone. One primary microphone and two secondary microphones.
Primary Mic:
The iPhone has a microphone located at the bottom of the phone on the left side; its primary job is to pick up the sound of your voice for phone calls. If you’re in a noisy environment, however, it also unavoidably gathers extraneous, unwanted sound.
Secondary Mic at Front/Rear Panel:
The main purpose of the secondary microphone, located at the back(sometimes at the front) of the iPhone 4, is to pick up ambient room noise. Because it sits at the opposite end of the phone from the primary mic, in a spot relatively isolated from your voice, it’s in a near-ideal position to collect the incidental sound and noise that surrounds you -but not your voice.
Secondary Mic at the Top:
Secondary microphone present at the top i.e near headset jack is used as the primary microphone while loudspeaker is in active mode. Primary mic is inactive when the loudspeaker is in ON.
Noise-Canceling Circuit
The iPhone’s noise-canceling circuit works by subtracting the signal from the secondary microphone from that of the primary. The primary microphone receives both ambient noise and your voice; the secondary mic picks up just the noise. After processing, the resulting signal consists primarily of your voice and has little room noise. When you make a phone call, the person at the other end of the conversation hears your voice clearly, as the iPhone removes distracting background noises.
