Hi everyone,
I am having problems with low quality mobile phone calls when submitting a audio file through it.
I am sending the calls with a VoiceXML compatible provider (Nexmo) and it seems that the mobile compression is messing up with my audio.
I have tried many file formats, rates, codecs, filters and effects. Still no good result.
IMHO, the audio seems muffled, or something like that. It’s happening only with male voices.
I think this is related to mobile phone codecs or compression.
Any ideas?
Thanks in advance,
Pedro Mazzoni
O.S.: Ubuntu 16.4 and Windows 10
There’s a reason “sounds like a cellphone” is a common description of sound distortion.
Cellphone transmissions are highly processed for efficiency, echo cancellation, frequency distribution, and volume compression.
One thing phones have done for centuries is emphasize tones in the 300Hz to 3000Hz range. Even done a little bit, tones like that can cut through interference and muffling and can carry clear conversation.
Entertainment transmission can be done classically by an extra cost, provisioned land-line (doesn’t sound like a phone any more) or dedicated data links (ISDN) with higher quality than the very restricted link for a voice call.
I think there was a technique where you could use slow, non-real-time transmission, but that’s not useful for interviews or other real-time work.
it seems that the mobile compression is messing up with my audio.
So, yes. That’s correct.
Koz
Thanks Kozikowski!
Entertainment transmission can be done classically by an extra cost, provisioned land-line (doesn’t sound like a phone any more) or dedicated data links (ISDN) with higher quality than the very restricted link for a voice call.
Unfortunately I don’t have a option, cellphone calls are required.
I think there was a technique where you could use slow, non-real-time transmission, but that’s not useful for interviews or other real-time work.
That’s not the case here, I need real-time interaction.
Then the cell system may not be the best bet. I’ve seen people do interviews over a mobile Skype or Chat connection. Those are restricted by the data channel, not the cell/voice channel. If the far end is on heasdsets, the communication quality can be quite good.
If you’re trying to do it like on the TV shows Let me put you on speakerphone so the whole room can talk to you, a lot of that is Hollywood. It must work perfectly and clearly. It says so here in the script.
Koz