| Name | Range (Hz) |
|---|---|
| Narrowband | 300–3,400 |
| Wideband | 50–7,000 |
| Superwideband | 50–14,000 |
| Fullband | 20–20,000 |
Wideband audio, also known as wideband voice or HD voice, is high definition voice quality for telephony audio, contrasted with 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 100 Hz to 17 kHz[2] but traditional, voiceband or narrowband 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.[3][1] In addition, some wideband codecs may use a higher audio bit depth of 16 bits to encode samples, also resulting in much better voice quality.[citation needed]
Wideband codecs have a typical sample rate of 16 kHz. For superwideband codecs the typical value is 32 kHz.[1]