title: Extended bandwidth nonlinear frequency compression in Mandarin-speaking hearing-aid users.
abstract: OBJECTIVE
  The high frequency information of consonant messages is important for recognition of speech. Recently, the nonlinear frequency compression (NLFC) technique has been shown to improve the speech perception in patients with high frequency hearing loss. In Mandarin, seven consonants are located over 10-16 kHz. Extended-bandwidth (EB) NLFC may provide an additional benefit for recognition of Mandarin words. The purpose of this study was to explore the effects of NLFC and EB-NLFC on Mandarin word recognition in patients with high frequency hearing loss.
  
  
  METHODS
  Fourteen native Mandarin-speaking adult patients, aged 20-65 years with bilateral, moderate to severe, sensorineural hearing loss, specifically high frequency hearing loss were included in single-blind randomized study. The assessment tools included the Mandarin Monosyllable Recognition Test (MMRT), Mandarin Hearing in Noise Test (MHINT), and International Outcome Inventory for Hearing Aids (IOI-HA) and sound quality scale of the hearing aids. The patients were tested under unaided condition, after which they were randomly assigned to wear NLFC and EB-NLFC hearing aids, alternatively, in a crossover fashion. After each 4-week block, the patients were tested again to obtain the test outcomes.
  
  
  RESULTS
  Patients with hearing aids with EB-NLFC had a significantly better word and consonant recognition using the MMRT (p<0.05). The MHINT was better for the EB-NLFC group without significant differences. The EB-NLFC group had better scores in both the IOI-HA and sound quality scale but not statistically significant.
  
  
  CONCLUSIONS
  Patients with high-frequency hearing loss may benefit more from using EB-NLFC for word and consonant recognition; however, the improvement was small under a noisy listening environment. The subjective questionnaires did not show significant benefit of EB-NLFC either.
authors.affiliation: Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Wen-Hsuan
authors.initials: WH
authors.lastname: Tseng
authors.affiliation: Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Dun-Lieh
authors.initials: DL
authors.lastname: Hsieh
authors.affiliation: Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Wan-Ting
authors.initials: WT
authors.lastname: Shih
authors.affiliation: Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: liuent@ntu.edu.tw.
authors.forename: Tien-Chen
authors.initials: TC
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D001302:Audiometry, Speech; D012048:Correction of Hearing Impairment / Q000295:instrumentation*; D005260:Female; D006310:Hearing Aids; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects; D017711:Nonlinear Dynamics; D019986:Persons with Hearing Disabilities / Q000534:rehabilitation*; D016037:Single-Blind Method; D013061:Speech Acoustics; D013067:Speech Perception; D055815:Young Adult
keywords: Mandarin Hearing in Noise Test; Mandarin Monosyllable Recognition Test; hearing aid; nonlinear frequency compression