It appears to me that you are hitting an OS restriction on open files (not only OS specific, but also installation specific of that OS).

But in any event it appears that you have too many open file handles - but I guess you know that.

From Audio::Wav

 
use Audio::Wav;
my $wav = new Audio::Wav;
my $read = $wav -> read( 'input.wav' );
[download]

If you somehow keep track of this $wav object via a reference to it an array of hash or array of array or whatever, I would assume that the file handle to 'input.wav' remains open.

$wav=undef; would cause that complete object to be destroyed and the file handle freed - right Now! - not when Perl exits.

Perl will destroy objects upon exit, but sometimes it is necessary to "take control" and do that for yourself. Maybe undef'ing the $read variable is all you need?

It would be very helpful if you could provide some actual code.