Fraunhofer (News - Alert) is a diverse organization with about 23,000 employees catering to applied research and development. The not-for-profit organization is divided into 66 institutes, one of which is IIS – best known for the invention of mp3. INTERNET TELEPHONY recently interviewed HP Baumeister, director at Fraunhofer USA, Digital Media Technologies, to learn what the company is up to in the HD voice realm.
What is Fraunhofer doing related to HD voice?
Quite a bit. But let me first clarify the term HD voice a bit. It refers to audio up to 7kHz bandwidth, which is less than half of the frequencies human hearing can cover. Just about all audio services such as streaming audio (with or without video), media downloads, broadcast services, DVDs/BD, etc., today offer CD-like quality, covering the full audio spectrum. We believe that communications should be no exception, and thus developed low latency versions of AAC (which can be seen as a second generation codec following mp3), providing the full audio bandwidth. We actually coined the term full-HD voice to help differentiate this much better quality.
Who’s using HD voice and how?
AAC-LD is used in practically all telepresence and videoconferencing systems, while AAC-ELD is the codec used in Apple’s (News - Alert) FaceTime service. In addition, AAC-ELD is now native in iOS, Mac OS and Android, and it is fair to say it is the most widely deployed super-wideband codec fulfilling the full-HD voice definition.
How exactly does this kind of HD voice compare with what we’re used to today?
Check out www.full-hd-voice.com, where we have audio clips to illustrate the performance of AAC-ELD, and compare it to narrowband and wideband codecs.
What’s next for HD voice?
Fraunhofer has been a key contributor to the next generation codec to be used in mobile telephony called Enhanced Voice Service. This codec was developed specifically for VoLTE services, which are clearly the future of mobile voice. EVS provides very high audio quality – at the full-HD voice level and even higher – at very low bit rates. EVS is now a 3GPP standard, and we can look forward to getting full-HD voice quality when making cell phone calls, quite possibly as early as a year from now.
Edited by Maurice Nagle