How to add and average 4 audio signals with arduino?

Hello, i need help to acquiring, adding and averaging four audio signals through analog inputs in the arduino uno, ¿any idea for this topic? I have been reviewing the LIFA library for this purpose and in one example of this library i get an audio signal is shown in labview.

Thanks anyone who can guide me

Are you sure this is the right device for your application?
Remember the Uno has only one ADC.

AWOL:
Are you sure this is the right device for your application?
Remember the Uno has only one ADC.

The Arduino has 7 ADC inputs multiplexed into one physical ADC.. So, it effectively has 7 ADCs and you certainly can get 7 separate analog readings from 7 different analog inputs.

It's only a 10-bit ADC, it's a bit slow for high-quality audio, and there is no true DAC, and there's not much RAM. So, the Arduino may not be the best choice for an audio processor, but with that out of the way...

Hello, i need help to acquiring, adding and averaging four audio signals

You've got it with "averaging"! Mixing is done by summation... Analog mixers are built around summing amplifiers, and when soundwaves mix in the air they are being acoustically summed.

So, you sum the data sample-by-sample (i.e. 44,100 samples per second for CD quality audio). That is, you sum the first sample from all four channels and the result becomes the first sample in your result/output channel. Repeat till done.

Now for the "averaging"... When you sum the values, of course the result is bigger (except sometimes you are adding a negative to a positive so every single sample won't be larger). That means you can clipping (or worse) if for example, you are using 16-bit audio and you go "higher than you can count" with 16-bits. So normally, you have to scale-down the result. You can scale down the values before summing, or after summing, or both. The easiest way would be to do the normal averaging thing, and divide the output values by 4.

With normal audio mixing, of course yo might want different volumes in each input. You adjust the volume by multiplication (or division) i.e You can reduce the volume in half (-6dB) by multiplying every value by 0.5. If you are not that familiar with audio, half the value doesn't sound like half the volume because our ears are logarithmic, and that's why we often use decibels.

So, it effectively has 7 ADCs and you certainly can get 7 separate analog readings from 7 different analog inputs.

What DVDdoug meant to say was, it has six inputs multiplexed into a single ADC, so each channel gets 1/6th the sample rate a single channel would get, which isn’t very fast to begin with (think low-end telephony)

Ok, now ... to perform the mixing of the 4 signals which device (Arduino) is recommended to use? Or is it possible to perform this task via software ?. Excuse my inexperience in this field. I appreciate all the help you are offering me. Thanks

The others are telling you that if you want quality audio, the Arduino is a very poor choice.