[asterisk-users] Silk for Free

[Steve Underwood]

Kevin P. Fleming wrote:
> Steve Underwood wrote:
>
>   
>> Good engineering of standards is about building them for the future. 
>> Cutting off the bass at 70Hz is far less of a limitation than cutting 
>> off the high end at 11kHz, but why do it in the codec? Why not leave the 
>> transducers and their amps to do what they can?
>>     
>
> Along those lines, I've mentioned here before that my wideband Polycom
> IP650 actually sounds substantially better with G.711 ulaw media streams
> than any previous phone I've had, and I've had high quality phones
> before. I can only assume this is due to the higher quality speakers,
> amps, microphones, and acoustic effects of the phone design.
>   
They might be doing some kind of fake bandwidth expansion. You can't 
create something out of nothing, and make the narrowband voice more 
intelligible, but you can make it sound pretty nice. Jean-Marc Valin (he 
of speex fame) has a very impressive expander he is working on at the 
moment.

Steve