Evaluating Audio and Video Quality in Low-Cost Multimedia Conferencing Systems

Abstract Real-time audio and video transmission over shared packet networks, such as the Internet, has become possible thanks to efficient data compression schemes and the provision of high-speed networks. Low-cost multimedia conferencing technology could benefit many users in different areas, such as remote collaboration, distance education and health-care. It is likely that diverse tasks performed by users in different application domains will require different levels of audio and video quality. Established methods of rating audio and video quality in the broadcast and telephony world cannot be applied to digital, lower quality images and sound. The providers of networks and services are looking to HCI to provide a means of assessing audio and video quality. The paper describes two different approaches to assessing audio and video of desktop conferencing systems — a controlled experimental study and an informal field trial. The advantages and disadvantages of both approaches for providing task-specific quality assessment are discussed, and future work to integrate lab-based and field trials into a valid and reliable assessment approach is outlined.

[1]  Gwyneth Doherty-Sneddon,et al.  Impact of Video-Mediated Communication on Simulated Service Encounters , 1996, Interact. Comput..

[2]  Robert H. McKim,et al.  Human engineering guide to equipment design , 1963 .

[3]  Stephen E. Deering,et al.  Multicast routing in internetworks and extended LANs , 1988, CCRV.

[4]  Steve Whittaker,et al.  Rethinking video as a technology for interpersonal communications: theory and design implications , 1995, Int. J. Hum. Comput. Stud..

[5]  Olov Östberg,et al.  Contribution of display size to speech intelligibility in videophone systems , 1989, Int. J. Hum. Comput. Interact..

[6]  Thierry Turletti,et al.  H.261 software Codec for videoconferencing over the internet , 1993 .

[7]  C. G. Rice.  Mechanisms of speech recognition , 1976 .

[8]  Ma Sasse,et al.  Remote Seminars through Multimedia Conferencing: Experiences from the MICE project , 1994 .

[9]  Nicholas Negroponte,et al.  Being Digital , 1995 .

[10]  J. Flanagan.  Speech Analysis, Synthesis and Perception , 1971 .

[11]  John Allnatt,et al.  Transmitted-picture assessment , 1983 .

[12]  Vicky Hardman,et al.  Lip synchronisation for use over the Internet: analysis and implementation , 1996, Proceedings of GLOBECOM'96. 1996 IEEE Global Telecommunications Conference.

[13]  E. Bard,et al.  Limited visual control of the intelligibility of speech in face-to-face dialogue , 1997, Perception & psychophysics.

[14]  Jean-Chrysostome Bolot,et al.  Analysis of Audio Packet Loss in the Internet , 1995, NOSSDAV.

[15]  Dolf Schinkel,et al.  Improved Speech Recognition Through Videotelephony: Experiments with the Hard of Hearing , 1991, IEEE J. Sel. Areas Commun..

[16]  Balaji Kumar.  Broadband Communications , 1995 .

[17]  Nils Björkman,et al.  Network Performance (NP) and its relationship with Quality Of Service (QOS) in an experimental broadband network , 1992, Broadband Communications.

[18]  G. A. Miller,et al.  The Intelligibility of Interrupted Speech , 1948 .

[19]  Anna Watson Angela Sasse.  Assessing the Usability and Effectiveness of a Remote Language Teaching System , 1996 .

[20]  Charles Foot.  Approaches to multimedia audio in language learning , 1994 .

[21]  Michael R. Macedonia,et al.  MBone provides audio and video across the Internet , 1994, Computer.

[22]  Henning Schulzrinne,et al.  Voice Communication Across the Internet: A Network Voice Terminal , 1992 .