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The Scientific World Journal
Volume 2013, Article ID 787656, 6 pages
Research Article

Development of a Low Cost Assistive Listening System for Hearing-Impaired Student Classroom

1Department of Computer Engineering, Faculty of Engineering, Chulalongkorn University, Phyathai Road, Patumwan, Bangkok 10330, Thailand
2National Electronics and Computer Technology Center, Rehabilitation Engineering and Assistive Technology Institute, 112 Thailand Science Park, Khlong Luang, Pathumthani 12120, Thailand

Received 29 March 2013; Accepted 7 May 2013

Academic Editors: A. Deveze and M. Stankovic

Copyright © 2013 Setha Pan-ngum et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This paper describes the design, development, and tests of a low cost ALS. It was designed for hearing-impaired student classrooms. It utilised digital wireless technology and was aimed to be an alternative to a popular FM ALS. Key specifications include transmitting in 2.4 GHz ISM band with eight selectable transmission channels, battery operated and chargeable, pocket size, and ranged up to thirty metres. Audio characteristics and user tests show that it is comparable to a commercial system, currently employed in our partner school. The results also show that wearing an ALS clearly improves hearing of hearing-impaired students. Long-term usage by school children will be monitored to evaluate the system robustness and durability.