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Purpose: The purpose of this work was to develop and evaluate a calibrated version of the Ling-6 sounds for evaluation of aided detection thresholds. Stimuli were recorded, and data from calibration values in dB HL were developed. Aided performance was characterized in adults and children.
Method: Stimuli were recorded, prepared, and transferred to a CD for testing. Initial testing was completed on 29 normally hearing young adults to determine typical responses in dB SPL and reliability. Corrections to dB HL were determined for each stimulus. Twenty-seven adults and 5 children with hearing losses were tested.
Results: Average normal sound field thresholds were 1 dB HL. Aided thresholds for adults varied with unaided hearing level and were better for low-frequency sounds. Adults and children performed differently, possibly because of greater hearing aid gain for children.
Conclusions: Stimulus preparation and shaping resulted in a recorded, calibrated set of Ling-6 stimuli that provide flat normal thresholds in hearing level for normally hearing listeners. Typical performance ranges may vary with hearing level and prescription. More data are required to fully characterize this trend in the pediatric population.
Key Words: amplification or hearing aids, children, adults, efficacy, outcomes
Intervention for permanent childhood hearing impairment typically follows four stages: screening, assessment, intervention, and outcome evaluation (American Academy of Audiology, 2003). For families choosing an oral-aural approach, intervention may include the fitting and use of hearing aids and/or cochlear implants as well as intervention for communication development. Therapists, including speechlanguage pathologists and auditory-verbal therapists, may be trained to screen for appropriate aided hearing prior to therapy sessions using the Ling-5 or Ling-6 sound test (Ling, 1989). The Ling-6 sounds include /m/, /u/, /a/, /i/, /X/, and /s/ and were chosen to span the range of speech frequencies typically occupied by running speech. In addition, the vowels /u/, /a/, and /i/ span the vowel quadrangle in the English language (Stevens, 1998). Preceding a therapy session, these sounds may be delivered using the therapist's voice, and the child's ability to detect and/or recognize each sound may be monitored. This rapid check is done to confirm that the hearing devices are functional and to assist the therapist in estimating the child's aided speech sound detection, identification, and discrimination abilities.
Because the Ling sounds are...