Efficacy of Linear Frequency Transposition on Consonant Identification in Quiet and in Noise
Background: Frequency transposition has gained renewed interest in recent years. This type of processing takes sounds in the unaidable high-frequency region and moves them to the lower frequency region. One concern is that the transposed sounds mask or distort the original low-frequency sounds and l...
| Published in: | Journal of the American Academy of Audiology |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Georg Thieme Verlag KG
2009
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.3766/jaaa.20.8.2 http://www.thieme-connect.de/products/ejournals/pdf/10.3766/jaaa.20.8.2.pdf |
| Summary: | Background: Frequency transposition has gained renewed interest in recent years. This type of processing takes sounds in the unaidable high-frequency region and moves them to the lower frequency region. One concern is that the transposed sounds mask or distort the original low-frequency sounds and lead to a poorer performance. On the other hand, experience with transposition may allow the listeners to relearn the new auditory percepts and benefit from transposition. Purpose: The current study was designed to examine the effect of linear frequency transposition on consonant identification in quiet (50 dB SPL and 68 dB SPL) and in noise at three intervals—the initial fit, after one month of use (along with auditory training), and a further one month of use (without directed training) of transposition. Research Design: A single-blind, factorial repeated-measures design was used to study the effect of test conditions (three) and hearing aid setting/time interval (four) on consonant identification. Study Sample: Eight adults with a severe-to-profound high-frequency sensorineural hearing loss participated. Intervention: Participants were fit with the Widex m4-m behind-the-ear hearing aids binaurally in the frequency transposition mode, and their speech scores were measured initially. They wore the hearing aids home for one month and were instructed to complete a self-paced “bottom-up” training regimen. They returned after the training, and their speech performance was measured. They wore the hearing aids home for another month, but they were not instructed to complete any auditory training. Their speech performance was again measured at the end of the two-month trial. Data Collection and Analysis: Consonant performance was measured with a nonsense syllable test (ORCA-NST) that was developed at this facility (Office of Research in Clinical Amplification [Widex]). The test conditions included testing in quiet at 50 dB SPL and 68 dB SPL, and at 68 dB SPL in noise (SNR [signal-to-noise ratio] = +5). The hearing aid ... |
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