Recording a Voicemail Message out of PT through Phone Patch

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jonnymo
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Recording a Voicemail Message out of PT through Phone Patch

Post by jonnymo » Thu Mar 01, 2007 1:38 pm

(Disclaimer: This doesn't pertain to recording music or instruments but to a specialized subset of recording audio. If I should be posting this somewhere else ? either in another section of the Tape Op forum, or in another forum altogether ? please let me know and I'll move it. Thanks.)

I am attempting to record a new voicemail message (voice with music background) for my studio by playing it out of Pro Tools LE through a Digi 002 into a Gentner SPH10 analog telephone hybrid, which is plugged directly into one of the 002's outputs. All the messages that I'm recording come back sounding both too quiet AND distorted. I know there's going to be a certain amount of distortion in the recording no matter what, since it's coming over the phone, but there seems to be in particular an extra high-end ?sizzle? audible over the whole pre-recorded message that is different from what one hears when listening to regular recorded messages.

Here's what I have tried to address the problem:
- compressing / limiting the recording in PT
- bringing the volume up / down in PT
- cutting out all the highs above 10 kHz or so (I don't remember the exact frequency, I EQ'ed it to sound like it was coming from a telephone line )
- recording the message by holding a phone up to one of the studio monitors instead of playing out of PT

I googled the junk out of this a few weeks ago...found out from http://docs.voxeo.com/voicexml/2.0/fram ... ormats.htm that telephony uses 8 kHz, 8-bit audio, and that automated phone response systems typically store their messages as audio files at this bit and sample rate. I considered converting the recordings to 8 kHz / 8-bit before playing them into the Gentner, but it doesn't seem like that would make a difference because I am recording the message to the voicemail via the phone line, as opposed to uploading a file that the system would play back.

So I guess what I'm wondering is: is there some kind of ?trick? to playing a pre-recorded message into a voicemail system that someone here might know about?

getreel
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Post by getreel » Sat Mar 03, 2007 11:07 am

I have no experience with a Gentner SPH10 but could you be overloading that? Could it be broken? Or maybe the system is optimized for a person speaking directly into a telephone? That's all I got.

getreel
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Post by getreel » Sat Mar 03, 2007 4:54 pm

Just after posting that last comment, I thought of something. but the board went down so now that it's back up...Is the Gentner supposed to have another Gentner on the other end to work properly? I don't know if that's how they work or not, but it seems like common sense that that type system would probably not work right single ended.

needlz
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Post by needlz » Sun Mar 11, 2007 10:58 pm

Aiit... this isn't a simple solution but many of us phone geeks use our own PBXs at home. Using a $60 old P3 desktop, a $40 analog telephony card, and a free linux distro of asterisk ( http://www.trixbox.org/ ) a world of voicemail possibilities opens up to you. I recently went to the eTel 2007 conference and heard the director of architecture at MySQL talk about the system he put in place for telemarketers... when a telemarketer calls he press *45 which fires an audio file of a SCREAMING monkey to the shocked telemarketer. The system them logs the callerID so everytime a call comes from that source the same audio file is played. Fargin' awesome. You can stream audio files as hold music, create a text to speech / speech recognition verion of Zork as a game for people on hold, interface any hardware in your house with your phone, etc, etc...

asterisk.org

needlz
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Post by needlz » Sun Mar 11, 2007 11:01 pm

The vm audio files are usually 8bit / 8khz / uLaw... uLaw being the factor you might be overlooking. Get an audio conversion app that supports uLaw exporting.

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