I hear a loud rustle on the audio message played by the PBX

When creating customized audio files for the PBX, it is necessary to check whether the software used (such as Adobe-Aution) queues text information files (typically in XML format) that are not audio samples. This information is still read by the PBX and generates an annoying noise (loud hiss) when the playback has finished.

So if you should feel this phenomenon open the file with an advanced text editor (eg. Notepad ++) and go to the end. If you notice XML-readable code such as
<x:xmpmeta xmlns:x=”adobe:ns:meta/” x:xmptk=”Adobe XMP Core 5.3-c011 66.145661, 2012/02/06-14:56:27 “>
<rdf:RDF xmlns:rdf=”http://www.w3.org/1999/02/22-rdf-syntax-ns#”>
then the file must be saved with another application, such as Goldwave or Audacity, which cuts this information away.