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Prompt wave file format

  • 1.  Prompt wave file format

    Posted 08-26-2019 11:49
    For a number of years I've always been told that the correct format for the prompt recordings was mu-law, 8 bit, 8kHz, mono; this is also stated in the InIn/Genesys documentation. Recently one of our customers complained about the quality of the recording, so I started to check the format on their system and I was surprised to see this:

    I went through several other recordings and they were all in the same format. Just to make sure I recorded a rest recording on Attendant and it came out in the same format.

    So I have two questions:
    - Is the recording format of  "mu-law, 8 bit, 8kHz, mono" not an absolute requirement anymore?
    - If the system is set to use a different format (as it seems to be the case here) is there any configuration that we can check to verify it so the recordings created outside of the system are in the right format? Or do we need to make a test recording with the Attendant to see what the format should be?

    Krzysztof Lipowski

  • 2.  RE: Prompt wave file format

    Top 25 Contributor
    Posted 08-27-2019 09:13

    I would extract one of the recordings and put it in an actual audio analysis application to confirm the format. I don't believe what you show in your screenshot is a standard format. Somehow the recordings managed to be recorded at 7Hz which is just crazy. Are you sure these recordings were recorded through Interaction Attendant and not something else and imported?


    Mark Tatera

    Opinions are my own and not the views of my employer. Any suggestions or programming changes I suggest come with no warranty and should be tried at your own risk.

  • 3.  RE: Prompt wave file format

    Posted 08-27-2019 11:03
    The need for "mu-law, 8 bit, 8kHz, mono" WAV format was introduced to help CIC(PureConnect) be more efficient in audio playback. If the requested prompt to play was in a different format, TSServer would have to convert it on the fly and it uses resources that could be better used elsewhere. Also, the conversion would not always yield a desired result in audio quality.

    In my experience, the biggest quality hit when converting is from stereo to mono. Whether the conversion is done by TSServer or a 3ed party tool, stereo to mono is a hard hit on quality. And there is no setting in the system to change the native format for playback within PureConnect.

    File recorded in Attendant should all be "mu-law, 8 bit, 8kHz, mono" .wav files. This function has not changed. When recording outside of Attendant, tools can be used to assure proper native format of the .wav files.

    Not sure if that helps at all but thought I'd contribute, best of luck.

    Chris Mayo
    Director, Technical Services

  • 4.  RE: Prompt wave file format

    Posted 09-04-2019 12:37
    Thanks Chris;

    If the system is converting those on the fly then no wonder that odd recording sounds not quite right - the client mentioned that, although it does not appear to be a major issue so far.
    I think I will have to extract the test recording I made in Attendant to see whether the format is really that weird or is that just Attendant that shows something incorrect.  I was hoping for someone form InIn/Genesys to add to this discussion but if not then I think I will just open a ticket with our service provider asking for explanation.

    Krzysztof Lipowski

  • 5.  RE: Prompt wave file format

    Posted 09-04-2019 12:29
    What is on this screenshot is my test recording done on Attendant, so yes, it's weird. The other recordings were done outside of the system by the third party and imported by the service provider (this is a system hosted by the third party) who should know what format is required. It all plays, but it's just not what i expected to see there.

    Krzysztof Lipowski

  • 6.  RE: Prompt wave file format

    Posted 09-04-2019 15:17
    I have verified the test recording file I made on the system and it seems to be in the right format: mu-law, 8 bit, 8 kHz, mono. I went then and checked how the recording format is displayed for our other customers. It turns out that the "0.007 kHz, 7 bit, Stereo" shows up only on version 2016R4. The 2017R4 displays the format correctly, and so does the 2018R2. So, this problem seems to be related to the version rather than to one particular installation. 

    Krzysztof Lipowski