[asterisk-users] Silk for Free

[Steve Underwood]

Steve Underwood wrote:
> 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.
>   
Someone tells me Polycom definitely do some form of bandwidth expansion, 
though its a lot less realistic than Jean-Marc technique.

Steve