Audio silence detection using silan (
Perl 6
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Audio silence detection using silan (

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use Audio::Silan;

my $silan =;

my $promise = $silan.find-boundaries($some-audio-file);

await $promise.then(-> $i { say "Start : { $i.start } End: { $i.end }" });


This module provides a mechanism to use Silan to detect the silence at the beginning and end of an audio file (which are sometimes described as cue in and cue out points.)

It allows the setting of the silence threshold and "hold off" (that is the minimum length of silence required before it is considered the end of the audio.) For certain material these values may need adjustment in order to provide accurate output.

Because the detection may take some time for larger files, this takes place asynchronously: the method find-boundaries returns a Promise which will be kept with the result of the detection (or broken if the detection failed.)


In order for this to work you will need a working installtion of Silan, this is often available as a package on Unix-like systems and you can use the appropriate package manager to install it. If it is not available as a package then it should be possible to install it from source.

Assuming you have a working Rakudo perl6 installation you should be able to install this with zef :

# From the source directory

zef install .

# Remote installation

zef install Audio::Silan

Other install mechanisms may be become available in the future.


Suggestions/patches are welcomed via github at:

It should be borne in mind before reporting an issue that this depends on the behaviour of silan itself and that is likely that any mis-reporting of the audio bounds is a result of silan itself or the parameters that are being used, I do know that version 0.3.2 of silan (which is frequently distributed with OS distributions,) may mis-detect for longer MP3 files (for example a 2 hour MP3 file may be detected as "ending" around the hour mark,) if this causes a problem to you then you should try upgrading the silan. This issue may also suggest that for certain types of file, the underlying libraries may also have an impact.


This is free software.

Please see the LICENCE file in the distribution

© Jonathan Stowe 2015, 2016, 2017