HD Voice explained

HD Voice captures sound waves twice as fast as other calls, and uses a broader range of frequencies to match the range of pitch and tone in human speech. This new technology improves the quality of voice calls by reducing background noise by using advanced noise cancellation technology.

HD Voice is essentially wideband audio technology that is usually used for conference calling and VoIP apps. A wideband audio call transmits at a range of 50 Hz to 7 kHz or higher, instead of limiting a call frequency to between 300 Hz and 3.4 kHz. This is much more in line with the human voice, which usually transmits audio between 75 Hz and 14 kHz.

HD Voice also takes in more audio samples per second than a standard call. Instead of 8,000 audio samples per second, HD Voice calls double that to 16,000. That way, you’re able to hear more details in a person’s voice during a call.