Workflow for recording and improving phone audio

[Ty Ford]

http://tyfordaudiovideo.blogspot.com/2014/06/handy-phone-recording-rig-improves.html

 

Regards,

 

Ty Ford

[Jay Rose]

Biggest problem with trying to record cell calls these days is the vocoding. When it's not confused, it's great. But if the transmitter hears two sounds that could both be formants in the same basic range, it often combines them or switches randomly, destroying intelligibility.

 

I've heard this (of course) with subjects who have radios going, or are on a train with a PA system... but also with non-vocal interferences like sirens and leaf blowers.

 

Oddest example I once heard was a subject in an echoey building lobby: the vocoder treated both her direct voice and the reverb as two equal voices, but the time delay meant that two vowels were sounding at the same time. Freaked the vocoder's analyzer out. When I asked the subject to move to a less echoey space, the voice cleared up like magic.

 

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BTW, the cleanest 'copper lines' I've heard are the packet-switched home POTS-equivalent ones provided by my local cable TV company. I compared sweeps between an RCN cable-tv line and a legacy Verizon "all-copper" one, local calls to my ISDN and then returning digitally... and the RCN was much better.

 

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BTW2, if you're just recording what's on the line, why not use a QKT instead of a hybrid? Far fewer analog components to get in the way: just a transformer and a cap.