Validity and reliability of in-situ air conduction thresholds measured through hearing aids coupled to closed and open instant-fit tips.
Audiometric measurements through a hearing aid ('in-situ') may facilitate provision of hearing services where these are limited. This study investigated the validity and reliability of in-situ air conduction hearing thresholds measured with closed and open domes relative to thresholds measured with insert earphones, and explored sources of variability in the measures. Twenty-four adults with sensorineural hearing impairment attended two sessions in which thresholds and real-ear-to-dial-difference (REDD) values were measured. Without correction, significantly higher low-frequency thresholds in dB HL were measured in-situ than with insert earphones. Differences were due predominantly to differences in ear canal SPL, as measured with the REDD, which were attributed to leaking low-frequency energy. Test-retest data yielded higher variability with the closed dome coupling due to inconsistent seals achieved with this tip. For all three conditions, inter-participant variability in the REDD values was greater than intra-participant variability. Overall, in-situ audiometry is as valid and reliable as conventional audiometry provided appropriate REDD corrections are made and ambient sound in the test environment is controlled.
O'Brien
Anna
A
National Acoustic Laboratories, Chatswood, Australia.
Keidser
Gitte
G
Yeend
Ingrid
I
Hartley
Lisa
L
Dillon
Harvey
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D001301:Audiometry, Pure-Tone / Q000295:instrumentation*; D001309:Auditory Threshold; D001844:Bone Conduction; D004867:Equipment Design; D005260:Female; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results