multi channel Audio input to PC through single microphone in MATLAB

Hi

I want to use microphone array for DoA estimation.For DoA estimation,I
require the data (which will be processed to find angle of arrival).I want
to know how to take input audio data on  PC .On my LAPTOP,i have only one
microphone input so how can I get multiple channels on single microphone
input.

Thanks

Salrome

_____________________________________
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Is it already listed at http://dsprelated.com/employers.php ?

salrome wrote:
> Hi
> 
> I want to use microphone array for DoA estimation.For DoA estimation,I
> require the data (which will be processed to find angle of arrival).I want
> to know how to take input audio data on  PC .On my LAPTOP,i have only one
> microphone input so how can I get multiple channels on single microphone
> input.
> 
> Thanks
> 
> Salrome

You can't (or at least, you really will not want to use analog 
multiplexing for such a task! And laptop mic inputs are rarely 
high-quality or noise-free).

A rather vital piece of information is: how many microphones? What type? 
Capacitor or dynamic? Capacitor microphones need external "phantom" 
power. Elecret mics (which can be pro quality) use internal batteries. 
And what sample rate and word length etc? What interfaces does your 
laptop have (e.g. USB 1 or USB 2? Firewire (4-pin or 6-pin)).

You will need an external soundcard (e.g. USB 1/2, Firewire if your 
laptop supports it). There are many such devices around at a wide range 
of prices, serving the pro, semi-pro and domestic audio markets (e.g. 
M-Audio, Roland (Edirol), Behringer, etc). High-end systems will provide 
8 channels or more, complete with phantom power  mic preamps (but use 
external power supply if conencting to the laptop via USB etc). Old USB 
1 cannot really handle more than about 6 channels (there is one Emagic 
device that managed it); for safety (and especially if wanting pro 
sample rates and 16bit audio or better) if using more than 4 mics, you 
would want USB 2 or Firewire.  If just using two microphones, there are 
many inexpensive USB-1 devices with built-in preamps that will do very 
nicely.

The alternative solution for multiple mics is  a portable mixer, 
sending line-level audio to simple line-input sound cards. Depends on 
what you are prepared to carry around, if that is an issue. You need 
decent hardware such as a mixer, and good preamps, as matching the 
levels will be a critical task.

Software to record multiple channels together is yet another matter.

Richard Dobson

On Apr 13, 10:06 pm, "salrome" <usman01as...@gmail.com> wrote:
> Hi
>
> I want to use microphone array for DoA estimation.For DoA estimation,I
> require the data (which will be processed to find angle of arrival).I want
> to know how to take input audio data on  PC .On my LAPTOP,i have only one
> microphone input so how can I get multiple channels on single microphone
> input.
>
> Thanks
>
> Salrome
>
> _____________________________________
> Do you know a company who employs DSP engineers?

> Is it already listed athttp://dsprelated.com/employers.php?
With the majority of sound cards you are limited to 2 mics. Beoyond
that you need either a special sound card or A/D convertors. You need
a pre-amp probably as well - one for each channel.

Wang King

>On Apr 13, 10:06 pm, "salrome" <usman01as...@gmail.com> wrote:
>> Hi
>>
>> I want to use microphone array for DoA estimation.For DoA estimation,I
>> require the data (which will be processed to find angle of arrival).I
want
>> to know how to take input audio data on  PC .On my LAPTOP,i have only
one
>> microphone input so how can I get multiple channels on single
microphone
>> input.
>>
>> Thanks
>>
>> Salrome
>>
>> _____________________________________
>> Do you know a company who employs DSP engineers?
>
>> Is it already listed athttp://dsprelated.com/employers.php?
>With the majority of sound cards you are limited to 2 mics. Beoyond
>that you need either a special sound card or A/D convertors. You need
>a pre-amp probably as well - one for each channel.
>
>Wang King
>
>

I have got the sound card Creative Audigy 4 pro for multiple microphone
input.I would be glad if some one has info regarding

1.How to connect multiple microphones to this card,which ports will be
used.
2.How can I read the audio data from the microphones through the sound
card in MATLAB
3-which additional equipment will be required for getting data into
computer


Best Regards
salrome



_____________________________________
Do you know a company who employs DSP engineers?  
Is it already listed at http://dsprelated.com/employers.php ?