# About Kinect Inner Structure; Microphone Array

• ### Question

I have question about kinect Inner Structure.

there are four MicroPhone.

1. Does each microphone have differences? (only position difference?)

2. microphone is placed, rate 1:3, why? (Left side is one microphone, Right side is three microphone.) is any reason to place like that?

and Thank you. I hope you to be happy everyday.

Tuesday, October 4, 2011 7:35 AM

• As far as I know all the microphones are identical. Seems to me that they have to be identical to use them accurately for SoundSourceLocalization.

As for the placement, I can't say why they did it but I can say that it is good to have at least 1:3 or 2:2 and not 0:4 placement. Having a "larger" distance between the 1st microphone and the others allows the user to see a difference between the inputs in terms of delay of sound.

When a sound comes from the side there is an approximate delay of up to 7 samples between the left most microphone and the centre microphone(at 16khz).

Hope this helped you in any way.

What I would have liked is a higher sample rate on the recording.... ( > 16khz)

Tuesday, October 4, 2011 9:29 AM

### All replies

• As far as I know all the microphones are identical. Seems to me that they have to be identical to use them accurately for SoundSourceLocalization.

As for the placement, I can't say why they did it but I can say that it is good to have at least 1:3 or 2:2 and not 0:4 placement. Having a "larger" distance between the 1st microphone and the others allows the user to see a difference between the inputs in terms of delay of sound.

When a sound comes from the side there is an approximate delay of up to 7 samples between the left most microphone and the centre microphone(at 16khz).

Hope this helped you in any way.

What I would have liked is a higher sample rate on the recording.... ( > 16khz)

Tuesday, October 4, 2011 9:29 AM

my realization is that left single microphone is for standard.

It is better to see picture below.

I am not sure this is right.

• Edited by Monday, October 10, 2011 10:12 AM
Monday, October 10, 2011 10:04 AM

see the Kinect then compare the size with your face;

camera's gap is almostly same with your eye's gap;

microphone's gap is also like your ear's gap.

and microphone is inside like your ear's diaphragm is inside.

it can make a source's flow same direction.

MS step into human robotics directly by Kinect;

• Edited by Wednesday, October 12, 2011 8:48 AM
Wednesday, October 12, 2011 8:44 AM