Cognitive skills and the effect of noise on perceived effort in employees with aided hearing impairment and normal hearing.

The aim of the following study was to examine the relationship between working memory capacity (WMC), executive functions (EFs) and perceived effort (PE) after completing a work-related task in quiet and in noise in employees with aided hearing impairment (HI) and normal hearing. The study sample consisted of 20 hearing-impaired and 20 normally hearing participants. Measures of hearing ability, WMC and EFs were tested prior to performing a work-related task in quiet and in simulated traffic noise. PE of the work-related task was also measured. Analysis of variance was used to analyze within- and between-group differences in cognitive skills, performance on the work-related task and PE. The presence of noise yielded a significantly higher PE for both groups. However, no significant group differences were observed in WMC, EFs, PE and performance in the work-related task. Interestingly, significant negative correlations were only found between PE in the noise condition and the ability to update information for both groups. In summary, noise generates a significantly higher PE and brings explicit processing capacity into play, irrespective of hearing. This suggest that increased PE involves other factors such as type of task that is to be performed, performance in the cognitive skill required solving the task at hand and whether noise is present. We therefore suggest that special consideration in hearing care should be made to the individual's prerequisites on these factors in the labor market.

Does retrieval strategy disruption cause general and specific collaborative inhibition?

The purpose of the experiment on collaborative memory was to investigate if the collaborative inhibition is due to collaborating pair's disruption of each others' retrieval strategies (the retrieval strategy disruption hypothesis, RSD). The participants' (N = 36) task was to recall a list of 60 words individually and collaboratively. Retrieval strategies were manipulated by presenting word lists organised either by categories or by country of origin and adoption of retrieval strategies were examined by the adjusted ratio of clustering score. Half of the dyads received word lists organised by the same strategy and half of the dyads received word lists organised by different strategies. The results revealed a main effect of collaboration, i.e., collaborative recalled items were significantly fewer than the sum of the non-redundant individually recalled items. Both conditions (same strategies vs different strategies) suffered to the same extent from collaboration, which did not support the RSD hypothesis. However, focusing on words recalled individually but not collaboratively, dyads with different strategies, as predicted by the RSD, forgot more items during collaboration than did dyads with the same strategy. Additional results suggest that collaborative forgetting is mainly manifested by forgetting of non-overlapping items (as measured by individual recalls).

The impact of different background noises: effects on cognitive performance and perceived disturbance in employees with aided hearing impairment and normal hearing.

BACKGROUND: Health care professionals frequently meet employees with hearing impairment (HI) who experience difficulties at work. There are indications that the majority of these difficulties might be related to the presence of background noise. Moreover, research has also shown that high-level noise has a more detrimental effect on cognitive performance and self-rated disturbance in individuals with HI than low-level noise. PURPOSE: The purpose of this study was to examine the impact of different types of background noise on cognitive performance and perceived disturbance (PD) in employees with aided HI and normal hearing. RESEARCH DESIGN: A mixed factorial design was conducted to examine the effect of noise in four experimental conditions. STUDY SAMPLE: A total of 40 participants (21 men and 19 women) were recruited to take part in the study. The study sample consisted of employees with HI (n = 20) and normal hearing (n = 20). The group with HI had a mild-moderate sensorineural HI, and they were all frequent hearing-aid users. INTERVENTION: The current study was conducted by using four general work-related tasks (mental arithmetic, orthographic decoding, phonological decoding, and serial recall) in four different background conditions: (1) quiet, (2) office noise at 56 dBA, (3) daycare noise at 73.5 dBA, and (4) traffic noise at 72.5 dBA. Reaction time and the proportion of correct answers in the working tasks were used as outcome measures of cognitive performance. The Borg CR-10 scale was used to assess PD. DATA COLLECTION AND ANALYSIS: Data collection occurred on two separate sessions, completed within 4 wk of each other. All tasks and experimental conditions were used in a counterbalanced order. Two-way analysis of variance with repeated measures was performed to analyze the results. To examine interaction effects, pairwise t-tests were used. Pearson correlation coefficients between reaction time and proportion of correct answers, and cognitive performance and PD were also calculated to examine the possible correlation between the different variables. RESULTS: No significant between-group or within-group differences in cognitive performance were observed across the four background conditions. Ratings of PD showed that both groups rated PD according to noise level, where higher noise level generated a higher PD. The present findings also demonstrated that the group with HI was more disturbed by higher than lower levels of noise (i.e., traffic and daycare setting compared with office setting). This pattern was observed consistently throughout four working tasks where the group with HI reported a significantly greater PD in the daycare and traffic settings compared with office noise. CONCLUSIONS: The present results demonstrate that background noise does not impair cognitive performance in nonauditory tasks in employees with HI and normal hearing, but that PD is affected to a greater extent in employees with HI during higher levels of background noise exposure. In addition, this study also supports previous studies regarding the detrimental effects that high-level noise has on employees with HI. Therefore, we emphasize the need of both self-rated and cognitive measurements in hearing care and occupational health services for both employees with normal hearing and HI.