Can You Hear Me Now? Benefits of Frequency-Modulated (FM) Systems for Adults and Children Using Cochlear Implants: A Meta-Analytic Approach Mary Pat Kleineck, Department of Speech and Hearing Sciences, College of Arts and Sciences & Honors College Faculty Mentor: Dr. Erin Schafer, Department of Speech and Hearing Sciences

Background What is a Cochlear Implant? –A cochlear implant is a surgically implanted hearing device that can significantly improve hearing for people with severe-to- profound hearing losses Picture from

Background What is a Cochlear Implant? –However, these devices do not restore hearing in noise and speech recognition abilities of the person with hearing loss often decline in the presence of background noise Picture from

Background What is an FM System? –An FM System is a type of assistive listening device which allows the listener to hear the desired speech signal at a louder level –It consists of a microphone, a receiver, and a transmitter, which carries the acoustic signal wirelessly from the microphone to the receiver

Background Types of FM Systems –Classroom soundfield Picture from

Background Types of FM Systems –Desktop soundfield Picture from

Background Types of FM Systems –Direct-Audio Input Picture from

Purpose To compare the improvements in speech recognition in noise for people who have cochlear implants when using classroom soundfield, desktop soundfield, and direct-audio input FM systems.

Methods Collected data from 8 studies from peer-reviewed journals and poster presentations from Inclusion criteria included: (1) testing done in Standard English, (2) testing of speech recognition, (3) testing of no-FM and FM conditions, (4) providing mean percent-correct and standard deviations for the data, and (5) a fixed intensity stimuli of +5 or +6 SNR.

Methods

Calculated differences between no-FM and FM-system conditions; each score was treated as a separate experiment Calculated average percent-correct scores and corresponding 95% confidence intervals for each experiment and type of FM system

Methods Performed a meta-analysis using a random-effects model. A chi-square value was computed to test the null hypothesis. Post-hoc analyses explored if the age of the listener, type of background noise, and type of internal processor used by the listeners yielded better speech recognition in noise with certain types of FM systems.

Results

Classroom Soundfield –Mean Average Benefit: 3.66% (CI 95 ± 7.29) –Intersects with 0% line –Results are not significant

Results Desktop Soundfield –Mean Average Benefit: 21.6% (CI 95 ± 7.4) –Does not intersect with 0% line –Results are significant

Results Direct-Audio Input –Mean Average Benefit: 36.8% (CI 95 ± 7.0) –Does not intersect with 0% line –Results are significant

Results Both desktop and direct-audio input offer significant benefits Direct-audio input provides the greatest benefit of all FM systems

Post-Hoc Findings The age of the participant does not affect the amount of FM-system benefit with classroom soundfield or direct-audio input receivers

Post-Hoc Findings The internal implant used by the participant did not affect results with a desktop soundfield receiver but did influence results with the direct-audio input receivers. Participants with Cochlear Corporation Nucleus 24 internal implants had significantly greater gains in speech recognition than those using a Cochlear Corporation Nucleus 22 internal implant.

Post-Hoc Findings The type of noise stimuli used during testing did not affect the amount of FM-system benefit measured for desktop soundfield and direct-audio input receivers.

Summary & Clinical Implications Though classroom soundfield FM systems are relatively inexpensive and easy to troubleshoot, they do not provide significant benefits Therefore, classroom soundfield FM systems should not be used in the schools

Summary & Clinical Implications Desktop soundfield and direct-audio input FM systems provide significant benefit Direct-audio input FM systems are superior and should be routinely recommended for children and adults with cochlear implants

Summary & Clinical Implications The post-hoc analysis suggests newer internal implant technologies work better with direct-audio input FM systems

Special Thanks To… Dr. Gloria Cox, Dean of the Honors College Dr. Susan Eve, Associate Dean of the Honors College Dr. Warren Burggren, Dean of the College of Arts & Sciences Dr. Samuel Matteson, Chair of the Department of Speech and Hearing Sciences