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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.
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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 www.uhhs.com
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 www.uhhs.com
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 www.oticon.com
Background • Types of FM Systems • Desktop soundfield Picture from www.centrumsound.com
Background • Types of FM Systems • Direct-Audio Input Picture from www.phonak.com
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 1998-2006 • 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% (CI95 ± 7.29) • Intersects with 0% line • Results are not significant
Results • Desktop Soundfield • Mean Average Benefit: • 21.6% (CI95 ± 7.4) • Does not intersect with 0% line • Results are significant
Results • Direct-Audio Input • Mean Average Benefit: • 36.8% (CI95 ± 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