3D Telephony

Telephony is a well-established and important tool for interpersonal communication. Despite the revolutionary expansion in the use of telephony brought about by IP-based services and mobile phones, telephony as a media has stagnated. Its speech and audio quality has hardly improved. Only recently, high fidelity audio transmissions have been supported by ITU G.719, CELT, and Bluetooth SBC audio codecs. But even with hi-fi stereo audio codecs one main limitation of telephone systems has not been solved. The location of the person speaking cannot be identified unambiguously. This adds to the problem of poor quality, especially in multi-user scenarios.

In a classic phone the acoustic origin of a remote speaker is always the phone of the listener. It would be more natural if the callers communicate as if they are standing in front of or next to each other, and if they are moving, the virtual source of the audio signal follows the speaker's movements. In this project we therefore aim to extend telephony into the third dimension. This will enable users to locate call participants in space, after all our ears and perception abilities are naturally binaural.

We work to develop a 3D Telephony System, which generates a virtual 3D acoustic environment in which each participant of a telephone call is placed at a unique position in the virtual world. The 3D Telephony System can be used for teleconferencing. Conference calls would be improved with regards to the listener's sensation of the call's quality because the participants will be able to identify the speaker by locating the origin of the sound. Also, many para- and nonverbal signs can be heard such as head or body movements due to changes of the acoustic delays and echoes.

This project is funded by HEC Pakistan and DAAD Germany.

Results

Installation, configuration and testing of a distributed interactive audiovisual virtual reality system.
Subjective listening only tests using a 3D audio rendering engine to study the impact of the virtual placement of the teleconference participants.
Basic design of 3D Telephony, which includes 3D sound rendering, 3D VoIP Phoneand Head Tracking.

Related Research

Following groups are also involved in relevant research.

Fraunhofer Institute for Integrated Circuits IIS, Germany.
Laboratory of Acoustics and Audio Signal Processing, TKK, Helsinki University of Technolog / Media Technolog , Finland.
Virtual AcousticTeam, Helsinki University of Technolog / Media Technolog.

Publications

[1]	Mansoor Hyder, Michael Haun, Olesja Weidmann, and Christian Hoene. Assessing virtual teleconferencing rooms. In Presented at the 129th AES Convention, San Francisco, CA, USA, November 2010.
[2]	Mansoor Hyder. Optimizing a 3D audio teleconference application. In ETSI QoS QoE User Experience Workshop - Focusing on speech / multimedia conference tools, Sophia Antipolis, France, September 2010.
[3]	Mansoor Hyder, Michael Haun, and Christian Hoene. Placing the participants of a spatial audio conference call. In IEEE Consumer Communications and Networking Conference - Multimedia Communication and Services (CCNC 2010), Las Vegas, USA, January 2010. [ .pdf ]
[4]	Mansoor Hyder, Michael Haun, and Christian Hoene. Measurements of sound localization performance and speech quality in the context of 3d audio conference calls. In International Conference on Acoustics, Rotterdam, Netherlands, March 2009. NAG/DAGA. [ .pdf ]
[5]	Mansoor Hyder and Christian Hoene. 3D telephony. ITU-T Workshop 'From Speech to Audio: bandwidth extension, binaural perception', September 2008. [ .pdf ]

Bibtex entries