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The Purpose of Sound Field

The Easy Listener™ sound field system is designed to deliver even amplification of the teacher's voice to all students in the classroom, regardless of where they are seated. It accomplishes this by improving the signal-to-noise ratio of the teacher's voice over room noise by 8-12 dB.
Sound field systems have been shown to:¹

• Improve academic achievement
  
• Improve speech recognition skills
  
• Improve attending and learning behaviors
  
• Increase seating options for students with mild hearing loss
  
• Improve listening and learning environments for "at-risk" learners (e.g., language-impaired, developmentally delayed, ADD, CAPD, LD, ESL etc.)
  
• Increase self-esteem
  
• Reduce teacher vocal strain and fatigue
  
• Increase ease of teaching
  
• Increase versatility of instructional techniques
  
• Increase teacher mobility.
  

1. Improving Classroom Acoustics, Florida Department of Education, 1993-1995)

A Room's Acoustics and How to Compensate for Them

A room's acoustics are affected by materials in the room that either absorb or reflect sound. Soft, porous items like padded furniture, carpeting, draperies - even people - muffle or absorb sound, while hard surfaces such as tiled or hardwood floors, chalkboards, bare cement walls, and windows reflect sound and cause reverberation. These acoustically absorptive and reflective materials, combined with classroom noise levels give each classroom its own acoustic characteristics. It is rare that all of these acoustic variables randomly produce an environment conducive to speech intelligibility.

The EASY LISTENER sound field system provides a way to overcome highly reflective, absorptive, and/or noisy environments by amplifying the teacher's voice and shaping the sound by means of a tone control. Similar to an equalizer on a home stereo, the tone control on the EASY LISTENER receiver allows the user to customize the sound to best fit the specific acoustics of the room - thus facilitating optimum speech intelligibility for the student.

Types of Speakers

AT664 Ceiling Speaker
The AT664 ceiling speaker is a specially-designed, ultra-low-profile speaker which installs quickly and easily into a standard 2'x2' acoustical ceiling tile grid. The rigid plastic construction is both durable and lightweight.

The unit's integrated array of four full-range speakers provides 180º x 360º hemispherical dispersion for maximum coverage.

AT578-S Wall Speaker
The AT578-S is a small, two-way bookshelf-type speaker similar to those used in home stereo and home theatre systems. An on/off switch allows teachers to quickly disable a portion of the listening area for multi-activity sessions within one room.

Types of Microphones

AT655 BTN Microphone
The AT655 behind-the-neck microphone is recommended for use with the EASY LISTENER sound field system. Its directional, noise-canceling capability combined with its constant proximity to the mouth assures maximum signal-to-noise ratio no matter which way the teacher is facing. This microphone provides the best sound quality and amplification of the consonant sounds critical to speech intelligibility. The AT655 can also be worn as a collar type microphone in cases where users are more comfortable with non-headworn accessories.

AT291 Directional Microphone
The AT291 directional lapel microphone is another high-quality option available to teachers who prefer the traditional clip-on/lavaliere type of microphone. This directional microphone eliminates lower frequencies that can mask the consonant sounds crucial to speech intelligibility. In addition, it can operate at high output levels without feedback.

For more information on Soundfield Systems, click here.