What's the data transfer speed of direct call (per second in Kbyte)?

[Ne Win Thowai]

It is told to be said that I need at least 60Kbyte/s speed for download and upload together for calling with Viber or with Skype. So, we normally use direct call before these kinds of app came to present. We use direct calls even if these kinds of app exist for the limited usage. Well, my question is, how much data (per second) does it transfer in the direct call (without usage of app)? Question came to my mind because I felt like asking this kinds of stuff, the direct call is more clarified than the app call.

Note: I have Googled, but no answer was there to satisfy me.

[Robsteriark]

Regular voice calls are not carried as data. On landlines they're transmitted as analogue signals, and on mobile phones they go to the cell tower via landlines as analogue signals and are then converted on the fly from analogue to digital to be sent to mobile phones and then the phone near instantly converts the signal from digital back to analogue.

Bandwidth gets used, but the portion of available bandwidth dedicated to digital data transmissions is not used. You therefore won't find the figures you seem as they don't exist.