Transmission of High-quality Sound via Networks Using Speech/Audio Codecs
Yutaka Kamamoto, Takehiro Moriya, Noboru Harada · NTT technical review · 2016
This article describes two recent advances in speech and audio codecs.One is EVS (Enhanced Voice Service), the new standard by 3GPP (3rd Generation Partnership Project) for speech codecs, which is capable of transmitting speech signals, music, and even the ambient sound on the speaker's side.This codec has been adopted in a new VoLTE (voice over Long-Term Evolution) service with enhanced highdefinition voice (HD+), which provides us with clearer and more natural conversations than conventional telephony services such as with fixed-line/land-line and 3G mobile phones.The other is MPEG-4 Audio Lossless Coding (ALS) standardized by the Moving Picture Experts Group (MPEG), which makes it possible to transmit studio-quality audio content to the home.ALS is expected to be used by some broadcasters, including IPTV (Internet protocol television) companies, in their broadcasts in the near future.