Microphone Array Strip

General project help for Adafruit customers

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
kvfranz
 
Posts: 15
Joined: Mon Dec 11, 2017 8:29 pm

Microphone Array Strip

Post by kvfranz »

Hello,

I would like to mimic a Alexa microphone array but instead of circle shape, I need it in a thin, linear strip using the same or similar microphones. Can anyone point me in the right direction to do so? I will be connecting this to a RPi or form factor computer.

Greatly appreciated!!

User avatar
adafruit_support_mike
 
Posts: 67446
Joined: Thu Feb 11, 2010 2:51 pm

Re: Microphone Array Strip

Post by adafruit_support_mike »

Making a row of microphones isn't hard, but writing the software to use them will take work.

I can't find any technical details in a quick search, but it's likely the code uses the microphones as nodes in an interferometry array.. combining the signals from all the mics to produce the equivalent of a single mic that's as large as the whole ring. That makes it more directionally sensitive, among other things.

Changing the shape of the microphone array changes the math necessary to do interferometry with the signals. The existing code probably wouldn't work, or would produce nonsense results. There's a strong chance that you'd have to build your own version of all that code, which is at least a medium-advanced challenge.

User avatar
adafruit_support_bill
 
Posts: 88086
Joined: Sat Feb 07, 2009 10:11 am

Re: Microphone Array Strip

Post by adafruit_support_bill »

As Mike says, lining up a bunch of microphones is the easy part. The signal processing is the hard part. MicroSemi makes a linear array microphone board - complete with a digital signal processing chip and associated software package.

https://www.microsemi.com/product-direc ... 32-zl38063

User avatar
kvfranz
 
Posts: 15
Joined: Mon Dec 11, 2017 8:29 pm

Re: Microphone Array Strip

Post by kvfranz »

Wow. Thanks for the insight Mike!

I found this kit which shows 4 microphones in a row. https://developer.amazon.com/alexa-voic ... cal-fusion

1) Do you think I can use this and will be easy to develop on?
or
2) Should I make my own microphone array and forgo this with a RPi itself?
or
3) None of the above...you have even better insight! haha

User avatar
kvfranz
 
Posts: 15
Joined: Mon Dec 11, 2017 8:29 pm

Re: Microphone Array Strip

Post by kvfranz »

Thank you Bill. That is super awesome. The link looks promising.

I would need someone to source and connect these pieces together or show me how for an RPi setup. This is a little over my head but am able to handle this task with guidance.

Let me know your thoughts. Thanks again! Greatly appreciated.

User avatar
adafruit_support_bill
 
Posts: 88086
Joined: Sat Feb 07, 2009 10:11 am

Re: Microphone Array Strip

Post by adafruit_support_bill »

I don't have a lot of experience with array mics, but it looks like there are a lot of development kits out there at a variety of price-points. Your best bet is probably to look for one with good manufacturer support and/or an active user forum.

This article reviews a few of the many options out there.
https://medium.com/snips-ai/benchmarkin ... 0de8876fda

User avatar
kvfranz
 
Posts: 15
Joined: Mon Dec 11, 2017 8:29 pm

Re: Microphone Array Strip

Post by kvfranz »

Hey Bill. Yes I saw this! Haha.

What is important is that the microphones are organized in a strip or linear fashion to fit into a particular space. Do you think I could assemble a MEMS microphone strip and then connect it to one of these dev kits to utilize their software? Or is it better to go a different route? Thanks again!

User avatar
adafruit_support_bill
 
Posts: 88086
Joined: Sat Feb 07, 2009 10:11 am

Re: Microphone Array Strip

Post by adafruit_support_bill »

The signal processing for a linear array is going to be different than for a circular array. So it will depend on whether their software package supports the configuration you need for your application. The MicroSemi clearly handles a linear array. And the 3-Eye looks like it may be a linear array as well. You would need to look at the documentation for the other packages to see what kinds of arrays they support.

User avatar
kvfranz
 
Posts: 15
Joined: Mon Dec 11, 2017 8:29 pm

Re: Microphone Array Strip

Post by kvfranz »

Ok. Great. I will look at these and dig in to see what they support.

If they do support a linear array, then the idea would be for me to build out the microphone array myself and connect to their software and/or hardware? Just want to confirm. Thanks.

User avatar
adafruit_support_bill
 
Posts: 88086
Joined: Sat Feb 07, 2009 10:11 am

Re: Microphone Array Strip

Post by adafruit_support_bill »

That is the theory anyhow. We are not the experts on these products. You will need to confirm with the manufacturer of the board what types of microphones and configurations are supported.

User avatar
kvfranz
 
Posts: 15
Joined: Mon Dec 11, 2017 8:29 pm

Re: Microphone Array Strip

Post by kvfranz »

oK. Thank you very much!!

Locked
Please be positive and constructive with your questions and comments.

Return to “General Project help”