In the scope of telephony and voice coding, Wideband refers to audio spectrum frequencies of 300–7800 Hz.

This spectrum allows for speech to traverse with good quality. This is also known as HD Voice.

It should be noted that the hearing spectrum of humans reaches 14 KHz and sometimes as high as 20 KHz. These higher frequency ranges are sometimes referred to as super-wideband and fullband.

In WebRTC, Opus offers wideband and up to fullband frequency support.