the codec doesn't use much bandwidth, but from what I have read about WMA Voice it seems that it needs much more processing power than standard WMA. Maybe this is the reason why this codec is not available for Analog Devices' Blackfin boards which power the SoundBridge.
BTW: I am not aware of any internet radio device supporting WMA Voice.
SoundBridge M1001 and M1000 • Clint L1 (retired) • DNT IP-dio (retired)
Google Chromecast • Amazon Fire TV • Amazon Echo and Echo Dot