Wideband audio, also known as HD voice, refers higher voice quality for telephony audio resulting in high definition voice quality compared to standard digital telephony “toll quality”.
It extends the range of audio signal frequency transmitted, result of this is higher quality speech. The range of the human voice range from 80 Hz to 14 kHz but traditionally, telephone voice-band or narrowband telephone calls limits audio frequencies to range of 300 Hz to 3.4 kHz. Wideband audio enables to transmit audio bandwidth in frequency range of 50 Hz to 7 kHz or higher.
First Sri Lankan Mobile Operator to prove HD Voice capability is Dialog Telekom in year 2012.
Then Etisalat join the game in 2014.