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.
Source : alltechbuzz.net
No comments:
Post a Comment