Amplification for Normal Hearing Children with APD?
Johnston et al (2009) reported that 10 children (average age 11 years, 8 months) with normal hearing and confirmed auditory processing disorder (APD) were recruited and fitted with FM systems. Thirteen normal hearing children served as controls (mean age 10 years, 6 months). Subjects were fitted with non-occluding, ear-level style FM systems. Parameters evaluated included speech perception, academic performance, and psychosocial status.
Upon conclusion of their study, Johnston et al noted that speech perception benefit (such as speech in noise tasks) from FM systems were greater for children with APD than for the control group—and the benefit improved significantly over time for the APD group. With regard to academic performance and psychosocial performance, children in the APD group showed improved performance in both categories after five months.
The authors reported potential long-term benefits from FM systems for the children in the APD group with regard to academics, emotional issues, psychosocial status, and improved speech perception ability. Hall et al (2010) reported that “These data provide strong evidence for the benefit of personal FM use in the classroom by children with APD.”
Kuk (2011) recently reported that when fitting hearing aids on children with APD, wide dynamic range compression (WDRC) should be used with a mild degree amount of gain and a very conservative MPO and directional microphones and noise reduction algorithms should also be considered. Kuk previously reported school-aged children with bilaterally symmetric (mild-to-severe) hearing loss demonstrated 20 percent improvement in speech recognition scores in noise (at a minus 7 dB SNR, with speech-shaped noise from the rear) using directional microphones.
Additionally, Kuk reports that noise reduction algorithms not only improve listening comfort but recent research has not demonstrated negative consequences of noise reduction (NR). Kuk suggests that the combination of directional mics and NR systems might be more beneficial (with regard to speech understanding in noise) than using omni mics only or while using omni mics with NR.
Kuk concludes that mini-sized BTEs with WDRC that provide approximately 10 dB of real-ear gain for soft sounds and fitted via open-ear could provide assistance to some children with normal hearing and APD, and the addition of NR and directional mics are “necessary features that have proven beneficial for improved speech understanding in noise.”
For More Information, References, and Recommendations
Hall JW, Johnston KN, John AB, Kreisman NV, Crandell CC. (2010) Multiple Benefits of Phonak Edulink Use By Children With Auditory processing Disorder (APD).
Johnston KN, John AB, Kreisman NV, Hall JW, Crandell CC. (2009) Multiple benefits of Personal FM System Use By Children With Auditory Processing Disorder (APD). International Journal of Audiology 48:371-383.
Kuk F. (2011) Hearing Aids For Children with Auditory Processing Disorders? Seminars in Hearing 32(2):189-195.