Enhanced Voice Services
(EVS)

Enhanced Voice Service (EVS) is a speech and audio codec developed by 3GPP for mobile telephony and communications. It supports audio content up to a bandwidth of 20 kHz. This makes it possible to use the codec not only for speech, but also for music and mixed content. It is the succesor of the AMR wideband (HD-Voice) codec.

The EVS codec supports various bit rates for different bandwidths:

• Narrowband (4kHz): 5.9, 7.2, 8.0, 9.6, 13.2, 16.4 and 24.4 kbit/s
• Wideband (8 kHz): 5.9, 7.2, 8, 9.6, 13.2, 13.2, 16.4, 24.4, 32, 48, 64, 96, 128 kbit/s
• Super Wideband (≥ 14 kHz): 9.6, 13.2, 13.2, 16.4, 24.4, 32, 48, 64, 96, 128 kbit/s
• Full Bandwidth (20 kHz): 16.4, 24.4, 32, 48, 64, 96, 128 kbit/s

The EVS codec is, for narrowband and wideband operation, backward compatible with its predecessor AMR.

The standardization was finalized at the end of 2014. The EVS codec is described in 3GPP TS 26.441 as part of Release 12.