Digital Noise Reduction and Speech Perception
It has been previously demonstrated that younger children with normal hearing and younger children with hearing loss do worse with regard to speech perception in noise, than do older children. Specifically, younger children need a better signal-to-noise ratio (SNR) than do older children (and adults) to perform at the same/similar level. Stelmachowicz et al (2010) report that previous adult-based studies have shown noise reduction (NR) does improve listening comfort and does decrease listening effort. However, NR does not improve or impair speech recognition in noisy backgrounds. The authors note that there were no previous studies that directly investigated the effects of digital noise reduction in children with hearing loss.
Therefore, Stelmachowicz et al evaluated 16 children (ages 5 to 10 years) with mild to moderately severe hearing loss. All participants wore modern digital behind-the-ear hearing aids programmed in accordance with DSL v. 5.0 and with a common NR strategy employed (modified spectral subtraction).
Consistent with previous studies, older children demonstrated higher speech recognition in noise than did younger children. However, the noise reduction "on-or-off" variable was not statistically significant. Specifically, the noise reduction circuit did not have a "differential effect" with regard to the children's ability to correctly identify speech sounds in noise.
Stelmachowicz et al stated that "It is encouraging that no significant differences were observed across NR conditions for nonsense syllables, words, or sentences..."
For More Information, References, and Recommendations
Stelmachowicz P, Lewis D, Hoover B, Nishi K, McCreery R, Woods W. (2010) Effects of Digital Noise Reduction on Speech Perception for Children with Hearing Loss. Ear & Hearing 31(3):345-355