Seminar by Nicolas Poncetti

Noise annoyance in open-plan offices: a study of the influence of mild hearing loss

Open-plan offices are the most common office layout in tertiary sector. Despite a noise level (50 to 60 dBA) below the regulations, occupants of these offices complain about noise. Among the various noise sources, co-worker’s voices and conversations – aka Irrelevant Speech Noise (ISN) – seem to be the most annoying one, as employee surveys have shown. In the laboratory, this phenomenon can be observed by two types of measures: (1) objective (performance during the accomplishment of a task) and (2) subjective (self-evaluation of the noise annoyance and questionnaires to measure, for example, their fatigue). So far, most of the participants in this kind of experiment are rather young people with normal hearing. This is not the case for all employees working in open-plan offices: they can be older (up to 65 yrs.) and have any level of hearing loss. The purpose of this study is investigating the effects of mild hearing loss (onset of presbycusis) on fatigue in an open-plan office – and more particularly under the influence of the ISN. Initially, studies carried out with normal-hearing people would be reproduced in hearing-impaired people, such as the analysis of the decrease in performance (DP) regarding the ISN’s intelligibility level. The difficulty finding several hearing-impaired people matching a similar audiogram led to the use of a hearing loss simulator (HLS) in normal hearing people. Volunteers performed the experiment in two hearing conditions: with and without a HLS. The results show a significant difference between the two hearing conditions, being the condition using HLS the least sensitive to ISN's intelligibility level.