Summary table of sound enhancement efficacy studies demonstrating improvement in speech-recognition skills
| Investigators |
Student Population |
Improvement in Speech Recognition
Obtained with SES*'s |
| Crandell & Bess (1986) |
20 students with normal hearing |
Students showed significant improvement in sentence recognition ability under the amplified condition in typical classroom (S/N = +6 DB, RT=0.6 sec). |
| Blair, Myrup & Viehweg (1989) |
10 students (CA=7-14 yrs) with mild to moderate SNHL |
Students with mild to moderate SNHL demonstrated an average of 12% improvement in word-recognition score when using personal hearing aids with FM sound field over hearing aids alone. |
| Jones, Berg, & Viehweg (1989) |
Kindergarten students with normal hearing (N=18) and mild hearing loss (N=18) |
Use of FM sound field amplification decreased student-teacher distance and produced word-recognition scores comparable to close listening at 4 feet. |
| Flexer, Millin, & Brown (1990) |
Primary school-age children with developmental disabilities |
Developmentally disabled students with history of persistent conductive hearing loss exhibited improved word-recognition scores. |
| Crandell (1993) |
20 students with normal hearing |
Significantly higher word-recognition scores were achieved by students at distances of 12 and 24 feet when using a SES* |
| Zabel & Tabor (1993) |
145 regular education 3rd through 5th grade students |
Students achieved improved spelling test scores under FM sound field amplification in quiet and under degraded listening at a +12 dB SNR. |
| Crandell (1996) |
20 nonnative English speaking children |
Improved speech-perception scores were achieved at distances of 12 and 24 feet when using a SES* |
| Allcock (1999) |
Three amplified and two unamplified elementary classrooms in New Zealand |
After 8 weeks of sound field amplification use, students in amplified classrooms showed a 65-74% improvement of 1 stanine on the Test of Phonological Awareness compared to students in unamplified classes showing a 46% improvement of 1 stanine. |
| Gordon-Langbein & Metinger (1999) |
2 elementary classrooms |
Students' abilities to identify initial consonant phonemes in words, using recorded questions, improved by 45% in the amplified conditions. |
| Eriks-Brophy & Ayukawa (2000) |
20 second and third-grade students (10 with hearing loss and 10 age-matched peers) |
Significant improvements in speech intelligibility were noted for recognition of Inuttitut syllables by both groups of students when using a SES*. |
| Lederman, Johnson, Crandell, & Smaldino (2000) |
72 third grade students (ELL, at risk, special education) and 9 third through fifth grade hard of hearing students |
Significant improvement on 16 of 40 listening tasks (words and CV syllables) and conditions (S/N at -6, 0,+6dB) using the SmartSpeaker "Intelligence" digital signal processing sound field system with ambient noise compensation (ANC) capability. |
| Prendergast (2001) |
31 third-grade and 33 fourth-grade students with normal hearing |
Enhanced performance was shown by all children on the California Consonant Test using the bending wave speaker vs. a traditional sound field speaker. |
| Mendel, Roberts, & Walton (2003) |
128 regular education kindergarten students with normal hearing |
2 year study showed significant and immediate improvement in speech perception and accelerated development of speech perception in noise by students in amplified classrooms. |
| Updike & Conner (2003) |
495 first-grade students in regular education classes |
Significant improvement in Goldman-Fristoe Test of Auditory Discrimination scores in quiet (76% to 92%) and noise (60% to 84%) |
