Study of the influence of the type of sound sources on the annoyance and performance at work in open-plan offices.

More and more frequently used by the companies of the tertiary sector, the open-plan office is a type of work organization which both enables to increase the occupation density and facilitates the oral communication between colleagues. Nevertheless, in such spaces, it appears a lack of privacy and an increase of sound levels. The GABO project, which deals with sound annoyance in open-plan offices, aims at defining indicators that should take into account the type of source identified in the open-space. In the first part of the project, it was shown, from in-situ surveys (Pierrette et al., ICA2013), that intelligible and non-intelligible conversations, ring tones and equipment noise (printers for instance) was among the sources that mainly contribute to the sound annoyance. Based on these results, the second part of the project is dedicated to the evaluation of the acoustic annoyance by means of laboratory experiments. 24 subjects have realized a short term memory task in five noisy environments, four containing a type of source (printers, intelligible speech, non-intelligible speech, ring tones) and one containing air-conditioning noise without any other source (control condition). At the same time, noise annoyance was subjectively evaluated and it has been possible to measure the decrease of performance depending on the type of source.