First off, make sure you  use strict; use warnings;

Secondly to figure out if you have that module run the command perl -MAudio::Wav -e 1 If you see output, it means you do NOT have it installed.

Your shebang line looks messed up, but if you're in windows, it doesn't matter.Edit: and I just noticed the title of your post says you're in ubuntu. Make sure your shebang lines points to the perl binary.

Update
I installed the module on my windows machine and tested your code. Nothing printed because your program doesn't say to print anything. See my code below for an output.

#!perl
use warnings;
use strict;
use Audio::Wav;

    my $wav = new Audio::Wav;
    my $read = $wav -> read( 'test_tone.wav' );
    my $details = $read -> details();
    use Data::Dumper;
        print Dumper($details)."\n"
[download]

It would appear that read() returns a reference to a hash. Since you're new, you're going to want to read up on hashes in perl and hash references.

To help you out a bit, the two lines I added to your program, use Data::Dumper is a module which will show you the internals of variables. The second line passes the variable details into Dumper() which exposes for us the internals.