#!/usr/bin/perl
use Audio::DSP;
#alsamixer must be setup right, AC'97 capture adjusts sensitivity, 
#just turn it up to 100 for this to work as intended 

($buf, $chan, $fmt, $rate) = (4096, 1, 16 , 8000);

$dsp = new Audio::DSP(buffer   => $buf,
                     channels => $chan,
                     format   => $fmt,
                     rate     => $rate);

$dsp->init() || die $dsp->errstr();

my $samples = 1500;
my $num_tot = 0;
my $div_tot = 0;

# Record x samples of sound 
for (1..$samples) {
        #read 16 bits of raw data 
        my $data = $dsp->dread(16) || die $dsp->errstr();
        my $num =  unpack( 'v', $data  );

        #filter out baseline noise 
        if($num > 65000){next}else{
            print  "$num\n";
            $num_tot += $num;
            $div_tot += 32768;  #gives a good average 
        }
 }

$dsp->close();

print "\n\nAverage ",sprintf('%0.2f',$num_tot/$div_tot),"\n";
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