Conference_programme: 18.4 - Office noise : psychological effects and room acoustic design

Lecture: In situ measurements of intelligibility in an open plan office

Author(s): D'Orazio Dario, Rossi Elena, Garai Massimo

Summary:
Acoustic comfort in open plan offices is a relatively recent research topic and some practices have not yet been consolidated. The goal in these spaces is a good speech privacy at every workstation, reaching a high value of spatial decay of the sound pressure level. In case of refurbishment a proper measurement of intelligibility criteria is needed, e.g. in order to properly calibrate a numerical model or to plan acoustic treatments. \nThe present work compares different measurement techniques to evaluate the spatial distribution of intelligibility criteria. Measured criteria include spatial reduction of STI, distraction distance and privacy distance. Spatial reduction of sound pressure level of normal effort speech and background noise were measured too. \n\emph{In situ} measurements were done in an open plan office used as case study. Both omnidirectional and directional sound sources with different sound power levels were used, according respectively to ISO 3382-3 and ITU p.51. Furthermore, compensation algorithms were used in impulse response measurements in presence of HVAC noise. In addition to this, subjective perception of the acoustic conditions was investigated by collecting the data of 53 workers. The values obtained with the campaign of measurements are in line with the results of the questionnaire: the acoustics of the open plan office is inadequate and some acoustic treatments are needed. Since each procedure returns various values, which values must be used in the design process? The study shows -- in a preliminary way -- how different techniques and equipment can influence intelligibility criteria used in the open plan office characterisation.

Corresponding author

Name: Dr Dario D'Orazio

e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Country: Italy