Korean J Otorhinolaryngol-Head Neck Surg.  2016 Feb;59(2):96-103. 10.3342/kjorl-hns.2016.59.2.96.

Early Experience of Non-Linear Frequency Compression Technology in Patients with High-Frequency Hearing Loss

• Kim J
• Park H
• Jin SH
• Park W
• Cho YS
• Hong SH
• Moon IJ

• KMID: 2155055
• DOI: http://doi.org/10.3342/kjorl-hns.2016.59.2.96

Abstract

BACKGROUND AND OBJECTIVES
Consonants are uttered in the high frequency range in speech to bring out understanding of our language. As consonants convey most of the word information, listeners with high-frequency hearing loss find it hard to understand speech. Non-linear frequency compression (NLFC) technology compresses and moves higher frequencies into a lower frequency region where better residual hearing is present. The purpose of this study was to evaluate clinical effectiveness of NLFC technology in patients with high-frequency hearing loss.
SUBJECTS AND METHOD
Twelve ears representing patients with sloping, high-frequency sensorineural hearing loss were involved in this study. Pure-tone audiometry and Threshold Equalizing Noise Test were conducted initially in all subjects. The subjects were tested in the counter-balanced order, and had two months of everyday experience with NLFC on/off before testing took place. A resting period intervened the two phases. Performance was repeatedly evaluated with Sound Field Audiometry, Word Recognition Score, Reception Threshold for Sentences and Korean version of International Outcome Inventory for Hearing Aids.
RESULTS
Cochlear dead region was detected on 4 kHz of both ears in only one subject. Each subject showed diverse performance and satisfaction with active NLFC condition. Typically, audibility of high-frequency pure-tones improved with NLFC-on condition. However, speech perception both in quiet and noise was not much improved when compared with NLFC-off condition.
CONCLUSION
The NLFC technology could improve audibility in high-frequency, but failed to demonstrate benefits regarding speech perception. Further research is needed to validate the effectiveness of the NLFC technology especially in terms of speech intelligibility.

Keyword

Hearing aids; High-frequency hearing loss; Non-linear frequency compression technology; Speech perception; Threshold Equalizing Noise Test

MeSH Terms

Audiometry
Audiometry, Pure-Tone
Ear
Hearing
Hearing Aids
Hearing Loss, High-Frequency*
Hearing Loss, Sensorineural
Humans
Noise
Speech Intelligibility
Speech Perception