Enable HD Voice without Root on your Android Devices
FIrst , what is HD Voice ?
Wideband audio, also known as HD voice, refers to the next generation of voice quality for telephony audio resulting in high definition voice quality compared to standard digital telephony “toll quality”. It extends the frequency range of audio signals transmitted over telephone lines, resulting in higher quality speech. The range of the human voice extends from 80 Hz to 14 kHz but traditional, voiceband ornarrowband telephone calls limit audio frequencies to the range of 300 Hz to 3.4 kHz. Wideband audio relaxes the bandwidth limitation and transmits in the audio frequency range of 50 Hz to 7 kHz or higher.
- Dial *#0011#
- Press Menu key,then Back
- Press Menu again then Key input,Enter value 1,and wait for few seconds
- Press Menu key,than Back
- Press  DEBUG SCREEN
- Press  WB-AMR SETTINGS
- Press  WB-AMR ENABLE
- Press Menu and then Back
- Finaly 9. Press  WB-AMR Status, VIOLA, WB-AMR SETTINGS: ON and UMTS WB: ON
if you’re success you may visit the official xda-developers thread for thanks/donate .