Introduction: In order to establish the acceptability of a hearing protector device (HPD) used in a given noisy environment, two key elements must be known with the highest possible accuracy: the insertion loss of the HPD and the associated variability. Methods leading to objective field measurements of insertion loss have become widely available in the last decade and have started to replace the traditional subjective “Real-Ear Attenuation at Threshold” (REAT) laboratory measurements. The latter have long been known to provide a gross overestimate of the attenuation, thus leading to a strong underestimate of the worker’s exposure to noise. Methods: In this work we present objective measurements of the insertion loss of an ear plug, carried out using the E-A-Rfit procedure by 3M on a large sample of 36 female and 64 male subjects. This large number of independent measurements has been exploited to calculate the distribution function of effective noise levels, that is noise levels that take into account the use of the HPD. The knowledge of the distribution function has in its turn allowed the calculation of the uncertainty on the effective noise levels. Results: This new estimate of uncertainty (6 to 7 dB) is significantly larger than most previous estimates, which range between 4 and 5 dB when using objective data but with an improper uncertainty propagation, and around 3 dB when using REAT subjective data. We show that the revised new estimate of uncertainty is much more realistic as it includes contributions that are missed by the other methods. Conclusions: By plugging this revised estimate of uncertainty into the criterion for checking the acceptability of the HPD, a better assessment of the actual protection provided by the HPD itself is possible.

Introduction: Two aspects of noise annoyance were addressed in the present laboratory study: (1) the disturbance produced by vehicle pass-by noise while engaging in a challenging non-auditory task, and (2) the evaluative response elicited by the same sounds while imagining to relax at home in the absence of a primary activity. Methods and Material: In Experiment 1, N = 29 participants were exposed to short (3-6 s) pass-by recordings presented at graded levels between 50 and 70 dB(A). Concurrent with each sound presentation, they performed a visual multiple-object tracking task, and subsequently rated the annoyance of the sounds on a VAS scale. In Experiment 2, N = 30 participants judged the sounds while imagining to relax, without such a cognitive task. Results and Discussion: Annoyance was reduced when participants were engaged in the cognitively demanding task, in Experiment 1. Furthermore, when occupied with the task, annoyance slightly, but significantly increased with task load. Across both experiments, the magnitude of simultaneously recorded skin conductance responses in the first 1-4 s after the onset of stimulation increased significantly with sound pressure level. Annoyance ratings tended to be elevated across all sound levels, though significantly only in Experiment 2, in participants classified as noise sensitive based on a 52-item questionnaire. Conclusions: The results suggest that noise annoyance depends on the primary activity the listener is engaged in. They demonstrate that phasic skin conductance responses may serve as an objective correlate of the degree of annoyance experienced. Finally, noise sensitivity is once more shown to augment annoyance ratings in an additive fashion.

Context: Several language variations of YANS have been published. There is a rationale in grouping languages where one variation is usable for several countries. The people of four ex-Yugoslavian countries do speak practically one language whatever its present name. Aim: To make a Serbian version of YANS which would be usable in Serbia, Croatia, Bosnia and Herzegovina and Montenegro. Settings and Design: Translation and test-retest survey in a secondary school. Material and Methods: The translation process was performed according to the relevant guidelines through a standard procedure: English-Serbian-English-Consensus (people fluent in English)-Pilot assessment (20 students). The survey was performed in a Belgrade high school. Test YANS was completed by 244 students (response rate 98,8%, males 44%). Retest YANS was carried out among 60 randomly chosen students from the primary sample (response rate 96.7%, males 58%). In the statistical analysis we used the Olsen’s model of classification as well as previous validation of YANS. A reliability measure for analyzing survey items was Cronbach’s alpha. Determination of the mean differences between test and retest with respect to normal distribution of data was performed with the Student’s paired t-test. Results: Factor analysis between items grouped into four factors showed no significant association, except for a weak but negative one between two specific factors. The internal reliability (Cronbach’s alpha) was 0.721 and assessed as acceptable. The test-retest comparison did not reveal any significant differences. Mean overall YANS score was 2.76, which is higher than on testing in Sweden, very similar to the Brazilian one, and lower than in Belgium and China. Conclusion: Serbian version of YANS is a valid and reliable research instrument. It may also be used in Croatia, Bosnia and Herzegovina and Montenegro.