in reply to Matching Incoming Audio Tones
Are there any signals you wish to ignore?
PDL::Audio ought to have a way to detect your signals, but the logic of what to respond to isn't clear if some aren't correct. If you must answer all pairs of two-second tones, you don't need to be selective, except for your own information.
After Compline,
Zaxo
In Section
Seekers of Perl Wisdom