Experimental technique for testing call audio quality?

[Helge Hafting]

Neil Jerram wrote:
> From the recent survey, it seems that several people are still
> experiencing bad call audio quality; and I've personally had some bad
> reports of this recently (and my phone has been buzz-fixed).
> 
> One of the problems, with trying to work on this, is finding a way to
> test audio quality repeatedly without spending lots of money on call
> charges and without taking up a lot of someone else's time (as the
> callee).  Can anyone suggest an experimental technique that is
> reliable - in the sense of being close enough to what really happens
> on a call - and that doesn't take a lot of money or someone else's
> time?
> 
> The best I've found so far is to call my work voicemail, speak to it,
> and get it to play my recording back to me.  But that's still costing
> a bit.  Any better ideas?
> 
To test the quality of analog components (mic, amplifier, speaker):

* Record voice (or test tones) to a file. Transfer the file to a
   computer with a good soundcard, to check quality.

* Get a sound file of known quality, transfer it to the FR.
   Play it (alsaplayer or some other audio player)
   and check the quality.

With this, you should get an idea of what sound the FR is
capable of. Tweak relevant volume settings; too little
is hard to hear, too much may clip and distort.

Calls will surely not be better than what you can get this
way. Ideally, you should be able to get calls up to
the same quality as this, by tweaking volume settings. Calls are digital 
  and shouldn't have sound distortion of its own. At least not worse 
than other phones.

The current default call volumes in SHR-U are quite bad, which may be 
the reason for many recent reports of audio problem. Anyone installing 
SHR-U should call themselves (on some other phone) and adjust both
mic volume and speaker volume.  (And then reboot the phone,
so the settings are saved.)

If the FR sound quality is too bad, consider a BT headset. Sound quality 
should then depend on the BT headset only. The FR's problems with buzz, 
bad bass, and possibly other analog issues shouldn't matter at all.

Helge Hafting