Measuring 3D Audio Localization Performance and Speech Quality of Conferencing Calls for a Multiparty Communication System MANSOOR HYDER*, GORDAN DAS MENGHWAR*, AND IMRAN ALI QURESHI** RECEIVED ON 03.05.2012 ACCEPTED ON 21.06.2012 ABSTRACT Communication systems which support 3D (Three Dimensional) audio offer a couple of advantages to the users/customers. Firstly, within the virtual acoustic environments all participants could easily be recognized through their placement/sitting positions. Secondly, all participants can turn their focus on any particular talker when multiple participants start talking at the same time by taking advantage of the natural listening tendency which is called the Cocktail Party Effect. On the other hand, 3D audio is known as a decreasing factor for overall speech quality because of the commencement of reverberations and echoes within the listening environment. In this article, we study the tradeoff between speech quality and human natural ability of localizing audio events/or talkers within our three dimensional audio supported telephony and teleconferencing solution. Further, we performed subjective user studies by incorporating two different HRTFs (Head Related Transfer Functions), different placements of the teleconferencing participants and different layouts of the virtual environments. Moreover, subjective user studies results for audio event localization and subjective speech quality are presented in this article. This subjective user study would help the research community to optimize the existing 3D audio systems and to design new 3D audio supported teleconferencing solutions based on the quality of experience requirements of the users/customers for agriculture personal in particular and for all potential users in general. Key Words: 3D Audio, VoIP, Telephony, Teleconferencing, Virtual Reality. * Assistant Professor, Information Technology Centre, Sindh Agriculture University, Tando Jam. ** Assistant Professor, Department of Telecommunication Engineering, Mehran University of Engineering & Technology, Jamshoro. 1. INTRODUCTION last decades; the number of user/customers for mobile and fixed lines phones has increased in many folds. On other side, there is hardly any improvement in the audio quality of phones. The chief limitation of the phones is extraneous noise, low speech intelligibility and poor audio Mehran University Research Journal of Engineering & Technology, Volume 32, No. 3, July, 2013 [ISSN 0254-7821] 373 Telephone is considered as one of the best inventions of the modern day world for communication with the people of all walks including businessmen, researchers and, students who often use this tool to communicate with their peers and market stack holders. Within the