Key Studies on Sound Field Amplification
The MARRS Project (1979 -1993)
Validated by the U.S. Department of Education
Soundfield FM Amplification: Theory & Practice Applications
C. Crandel, J. Smaldino and C. Flexer
- 30% of average elementary (K-6) populations fail a 15dB screening test.
- Most of these children have this mild hearing loss due to otitis media (infections) and middle ear fluid.
- A smaller percentage have chronic mild hearing loss (MHL) and a larger percentage is affected periodically throughout a given school year.
- The majority of these children go undetected since thy usually pass a routine screening of 25dB. This level has traditionally been though to be adequate for normal classroom hearing.
- 75% of these MHL children have academic deficiencies by the 6th grade
- Many of the unidentified MHL students are misdiagnosed with various learning difficulties.
- Teaching quality is enhanced as every child receives clearly audible instructions, regardless of background noise or seating location.
- There are statistically significant improvements in reading and language test scores for K-6 students, both those with normal hearing and those with mild hearing loss.
- The significant gains in academic scores were clearly evident in less than one school year and were maintained for the study periods of up to three years.
- Sound-field audio was lower cost than resource room instruction to achieve the same or superior academic test scores
- Teachers reported that classroom management was improved and discipline problems were reduced due to better voice command response throughout the classroom.
- Most students reported that they found it easier to understand and pay attention.