Noise is omnipresent and impacts us all in many aspects of daily living. Noise can interfere with communication not only in industrial workplaces, but also in other work settings (e.g. open-plan offices, construction, and mining) and within buildings (e.g. residences, arenas, and schools). The interference of noise with communication can have significant social consequences, especially for persons with hearing loss, and may compromise safety (e.g. failure to perceive auditory warning signals), influence worker productivity and learning in children, affect health (e.g. vocal pathology, noise-induced hearing loss), compromise speech privacy, and impact social participation by the elderly. For workers, attempts have been made to: 1) Better define the auditory performance needed to function effectively and to directly measure these abilities when assessing Auditory Fitness for Duty, 2) design hearing protection devices that can improve speech understanding while offering adequate protection against loud noises, and 3) improve speech privacy in open-plan offices. As the elderly are particularly vulnerable to the effects of noise, an understanding of the interplay between auditory, cognitive, and social factors and its effect on speech communication and social participation is also critical. Classroom acoustics and speech intelligibility in children have also gained renewed interest because of the importance of effective speech comprehension in noise on learning. Finally, substantial work has been made in developing models aimed at better predicting speech intelligibility. Despite progress in various fields, the design of alarm signals continues to lag behind advancements in knowledge. This summary of the last three years’ research highlights some of the most recent issues for the workplace, for older adults, and for children, as well as the effectiveness of warning sounds and models for predicting speech intelligibility. Suggestions for future work are also discussed.

RÉSUMÉ But : Effectuer une traduction franco-canadienne de la PEDro scale sous l'appellation proposée d'Échelle PEDro et examiner la validité de son contenu. Méthodologie : Nous avons utilisé une approche modifiée de la méthodologie de validation transculturelle de Vallerand. Une traduction renversée parallèle de la PEDro scale a d'abord été effectuée à la fois par des traductrices professionnelles et des chercheurs cliniciens. Ensuite, un premier comité d'experts (P1) a examiné les versions traduites et a créé la première version expérimentale de l'Échelle PEDro. Cette version a été évaluée par un deuxième comité d'experts (P2). Finalement, 32 chercheurs cliniques ont évalué cette deuxième version expérimentale de l'Échelle PEDro à l'aide d'une échelle de clarté (étendue de 5 points) et ont proposé les modifications finales. Résultats : Pour les différents énoncés de la version finale de l'Échelle PEDro, les moyennes sur l'échelle de clarté montrent un niveau élevé puisqu'elles varient entre 4,0 et 4,7 sur un score maximal de 5 points. Conclusion : Les quatre étapes rigoureuses du processus ont permis de produire une version franco-canadienne valide de l'Échelle PEDro.

A psychoacoustic model is presented to facilitate the installation of acoustic warning devices in noisy settings, reflecting a major upgrade of a former tool, Detectsound. The model can be used to estimate the optimal level and spectrum of acoustic warning signals based on the noise field in the workplace, the hearing status of workers, and the attenuation provided by hearing protectors. The new version can be applied to a wider range of situations. Analyses can now be conducted to meet the functional requirements for a specific worker or to suit the needs for a group of co-workers sharing a work area. Computation of optimal warning signals can also be made from estimated hearing parameters based on the worker age, gender, and level and duration of noise exposure. The results of a laboratory validation study showed that the mean error in estimating detection thresholds for normal hearing individuals is typically within ±1 dB with a standard deviation of less than 2.5 dB in white noise or continuous noise fields. The model tends to yield slightly overestimated warning signal detection thresholds in fluctuating noises. Proper application of the tool also requires consideration of the variability in estimating noise levels, hearing status, and hearing protector attenuation under field conditions to ensure that acoustic warning signals are sufficiently loud and well adjusted in practice.

Objective: This study explored the effects of hearing protection devices (HPDs) and head protection on the ability of normal-hearing individuals to localize reverse alarms in background noise. Background: Among factors potentially contributing to accidents involving heavy vehicles, reverse alarms can be difficult to localize in space, leading to errors in identifying the source of danger. Previous studies have shown that traditional tonal alarms are more difficult to localize than broadband alarms. In addition, HPDs and safety helmets may further impair localization. Method: Standing in the middle of an array of eight loudspeakers, participants with and without HPDs (passive and level-dependent) had to identify the loudspeaker emitting a single cycle of the alarm while performing a task on a tablet computer. Results: The broadband alarm was easier to localize than the tonal alarm. Passive HPDs had a significant impact on sound localization (earmuffs generally more so than earplugs), particularly double hearing protection, and level-dependent HPDs did not fully restore sound localization abilities. The safety helmet had a much lesser impact on performance than HPDs. Conclusion: Where good sound localization abilities are essential in noisy workplaces, the broadband alarm should be used, double hearing protection should be avoided, and earplug-style passive or level-dependent devices may be a better choice than earmuff-style devices. Construction safety helmets, however, seem to have only a minimal effect on sound localization. Application: Results of this study will help stakeholders make decisions that are more informed in promoting safer workplaces.

Objective: To measure masked detection and reaction thresholds for two reverse alarms (tonal and broadband) and compare results to available standards and psychoacoustic criteria for setting alarm levels. Design: Alarm detection and reaction thresholds were adaptively measured in 80-dBA background noises without hearing protection (Experiment 1), and with a passive earmuff-style hearing protection device (HPD) (Experiment 2). Study sample: Twenty-four young adults with normal hearing in each experimental group. Results: Reverse alarms remained audible at levels well-below background noises [thresholds: -11 to -25 dB signal-to-noise ratio (SNR)], with and without the selected HPD. Detection was more influenced by alarm and noise type, while reaction was more susceptible to HPD use. HPD use resulted in lower detection thresholds by up to 2.5 dB compared to unprotected listening but increased reaction thresholds by 5-10 dB depending on the alarm. Conclusions: Since noise type appears to have a more limited effect on reaction thresholds, adjusting alarms based on a global dBA method appears preferable to methods based on masked detection thresholds. However, while the >0 dB SNR recommended in ISO 9533 seems adequate for unprotected listening, an additional 5-10 dB may be warranted to elicit the same reaction when the selected HPD is used.