Currently, the tone-generator uses the overall system volume to dictate what volume the key press tones are played at. At the default setting it is really loud and forces the user to turn down the overall system volume to limit this, which is not desireable.
The tone-generator should be fixed to do one of the following:
1) always play at a fixed volume, like some reasonable percentage of the max volume, i.e. 20%
2) respond to overall volume changes of the system volume at a reduced percentage. For example tone-generator volume range would be 0-30% of the adjusted volume controlled by the slider. This is how iOS works so you can still adjust the tones but they never get louder than a certain point.
NOTE: tone-generator playback should be disabled when silent-mode is on or a tone-dialer specific setting is disabled, but this is a separate issue.
I agree that the default is currently too loud.
> The tone-generator should be fixed to do one of the following:
> 2) respond to overall volume changes of the system volume at a reduced percentage.
It should do that already, but I'll test in detail tomorrow.
The maximum level is defined in the tone-generator upstart session file (variable DTMF_VOLUME), as a percentage (0..100) of the system volume, (seems to be quite non-linear, e.g. 20 is way louder than 10).
The volume slider is obeyed - but after reboot sometimes forgotten, see bug 598308.
I'll give more detail after testing, but also cc:ing Ricardo, he is working on bug 598308 as well as the overall system default volumes.