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Objective: To study the effect of a large number of repetitions on the most comfortable level (MCL) when doing the acceptable noise level (ANL) test, and explore if MCL variability is related to central cognitive processes. Design: Twelve MCL repetitions were measured within the ANL test using interleaved methodology during one session using a non-semantic version. Phonological (PWM) and visuospatial working memory (VSWM) was measured. Study sample: Thirty-two normal-hearing adults. Results: Repeated measures ANOVA, intraclass correlations, and the coefficient of repeatability (CR) were used to assess the repeatability. Repeated measures ANOVA and CR indicated poor agreement between the two first repetitions. After excluding the first repetition, analyses showed that the MCL in the ANL test is reliable. A negative association was found between PWM and MCL variability indicating that subjects with higher PWM show less variability. Conclusions: The findings suggest that, after excluding the first repetition, the MCL in the ANL test is reliable. A single repetition of the MCL in the ANL test should be avoided. If an interleaved methodology is used, a single ANL repetition should be added prior to the actual testing. The findings also suggest that MCL variability is associated to PWM but not VSWM. [ABSTRACT FROM AUTHOR]

Objective: This study explores if increasing number of repetitions might improve the precision of the acceptable noise level (ANL) test. Design: We measured twelve ANL repetitions, i.e. four complete ANL tests (4 × 3 repetitions), at one session using diotic presentation and a non-semantic ANL version. Study sample: Thirty-two normal-hearing adults. Results: Small order and fatigue effects were seen. We used the coefficient of repeatability (CR) to assess the repeatability; CRs ranged between 3.9 and 7.6 dB for the four ANL tests. Using the twelve ANL repetitions we removed the variability of the ANL across subjects by normalizing the data to the individual mean ANL for the twelve repetitions. The mean normalized ANL across the subjects rapidly approached the ANL normalized to the individual mean for the 12 repetitions (0 dB), and after three repetitions the SD seemed to be stable at about 3 dB. Conclusions: The findings suggest that both order and fatigue affect the ANL. The findings also suggest that it may be more accurate to speak of an acceptable noise range than ANL. These findings have large implications for how we understand acceptable noise and it would explain a large part of the variability seen among normal-hearing and perhaps hearing-impaired subjects. [ABSTRACT FROM AUTHOR]