In honor of the US government's new National Do Not Call Registry, I give you a script to generate those three little tones that telemarketing computers hate to hear...
Special Information Tones to the rescue!
#!/usr/bin/perl -w use strict; use Audio::Wav; my $sample_rate = 8000; my $bits_sample = 8; my $num_channels = 1; my $pi = 4 * atan2 1, 1; my $max_no = ( 2 ** $bits_sample ) / 2; my @tones = map { 2 * $pi * $_ } (985.2, 1370.6, 1776.7); # in Hz my @dur = map { $sample_rate / 1000 * $_ } (380, 274, 380); # in ms my $details = { 'bits_sample' => $bits_sample, 'sample_rate' => $sample_rate, 'channels' => $num_channels, }; my $wav = new Audio::Wav; my $write = $wav->write( 'sit.wav', $details ); for ( 0 .. 2 ) { for my $pos ( 0 .. $dur[$_] ) { $write->write( $max_no * sin( $pos / $sample_rate * $tones[$_] ) ) +; } } $write->finish();
In reply to Do Not Call! by Mr. Muskrat
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