World Library  

Add to Book Shelf
Flag as Inappropriate
Email this Book

Assistive Listening Systems Bulletin 9B : For Installers

By United States Access Board

Click here to view

Book Id: WPLBN0000703186
Format Type: PDF eBook
File Size: 286.64 KB.
Reproduction Date: 2005
Full Text

Title: Assistive Listening Systems Bulletin 9B : For Installers  
Author: United States Access Board
Language: English
Subject: Government publications, Access Board, Architectural and Transportation Barriers Compliance Board
Collections: U.S. Access Board Collection
Publication Date:
Publisher: United States Access Board


APA MLA Chicago

Access Board, U. S. (n.d.). Assistive Listening Systems Bulletin 9B : For Installers. Retrieved from

Government Reference Publication

Excerpt: How do assistive listening systems (ALS) interface with public address (PA) systems? Public address systems are, in fact, assistive listening systems. They are designed to help people hear across a distance. In a PA system, the sound is picked up at a microphone and delivered through speakers that bring the amplified sound closer to listeners in an audience. For many people and in many circumstances, a loudspeaker may provide enough gain in volume for adequate speech perception. But no matter how well-placed the loudspeaker(s), perception of air-borne speech signals will be difficult for people with hearing loss unless background noise and reverberation can be carefully controlled. The same microphone pick-up used in the PA system can also serve an assistive listening system (ALS or ALD). By bridging the acoustical space between the source and the listener, an ALS circumvents the effects of distance (drop in volume), background noise (competing sound), and reverberation (reflecting sound that blurs the desired signal).


Click To View

Additional Books

  • Accessible Pedestrian Signals (by )
  • Accessible Swimming Pools and Spas (by )
  • Accessible Sports Facilities (by )
  • Accessible Sports Facilities (by )
  • Accessible Miniature Golf (by )
  • Accessible Miniature Golf (by )
  • Accessible Golf Courses (by )
  • High-Speed Rail Cars, Monorails and Syst... (by )
  • Rapid Rail Vehicles & Systems Technical ... (by )
  • Rapid Rail Vehicles & Systems Technical ... (by )
  • Intercity Rail Cars and Systems Technica... (by )
  • Intercity Rail Cars and Systems Technica... (by )
Scroll Left
Scroll Right


Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.