The effect of speech presentation level on measurement of auditory acclimatization to amplified speech

Abstract

A systematic improvement in auditory performance over time, following a change in the acoustic information available to the listener (that cannot be attributed to task, procedural or training effects) is known as auditory acclimatization. However, there is conflicting evidence concerning the existence of auditory acclimatization; some studies show an improvement in performance over time while other studies show no change. In an attempt to resolve this conflict, speech recognition abilities of 16 subjects with bilateral sensorineural hearing impairments were measured over a 12-week period following provision of a monaural hearing instrument for the first time. The not-fitted ear was used as the control. Three presentation levels were used representing quiet, normal, and raised speech. The results confirm the presence of acclimatization. In addition, the results show that acclimatization is evident at the higher presentation levels but not at the lowest.

Late auditory evoked potentials in elderly long-term hearing-aid users with unilateral or bilateral fittings

“…The SPIN-test was presented to the hearing-impaired 438 subjects at constant noise levels above 80 dB SPL (see Table 1). Our results are in line 439 with those of Munro and Lutman (2003), who reported an acclimatization effect after 12 440 weeks of hearing-aid use, when using speech in noise at the highest presentation level 441 of 69 dB SPL, but only minimal for 55 and 62 dB SPL. Gatehouse (1989) also reported 442 that the aided ears performed better only at high presentation levels (>75 dB SPL), 443 while at lower presentation levels the unaided ear was advantaged.…”

Benefit from, and acclimatization to, frequency compression hearing aids in experienced adult hearing-aid users

“…However, baseline measures were not obtained immediately after fitting so it is impossible to ascertain from the data how much acclimatisation may have taken place within the initial six weeks of use. Previous research of acclimatisation to conventional hearing aids has shown that significant changes may take place in the initial six weeks post fitting (Gatehouse, 1992;Munro and Lutman, 2003). A further issue that may influence the validity of these results stems from the fact that there was no control group for the measurements taken after 6 months of frequency compression use.…”

Reconhecimento de fala segundo o tempo de uso da amplificação

“…7 Auditory perceptual acclimatization is a systematic change in the auditory system with time. 18 There is an evident conflict about the existence of perceptual acclimatization, 19 as some studies have shown improved performance while other have failed to demonstrate the effects of auditory perceptual acclimatization. There are at least three explanations for the studies that did not find perceptual acclimatization.…”

“…22 Thirdly, findings may attempt to demonstrate perceptual acclimatization based on inappropriate levels in test materials, and thereby often fail. 19 Based on these statements, it is possible to question the effective use of hearing aids during our study period in adult and elderly subjects that showed no change in speech recognition with time. If about 50% of subjects showed improved SRTS and SRTN tests, then why did the other half show not changes or even worse results?…”

“…There are at least three explanations for the studies that did not find perceptual acclimatization. 19 Firstly, subjects may have had few opportunities for improvement because of minor hearing losses, 20 or may have had prior experience with hearing aids, 21 or may have used hearing aids in a limited manner. 20,21 Secondly, negative findings may occur if the methods fail to measure the changes that actually occur.…”