Abstract:

This paper will review recent work that has considered speech privacy criteria in open-plan offices and the development of new procedures to assess the architectural speech security of closed offices and meeting rooms. For open-plan offices, new subjective studies have confirmed the validity of a speech privacy design goal of SII no more than 0.20 (AI 0.15) and that an ideal masking noise level is ~45 dBA. For the speech security of closed meeting rooms, subjective studies have developed new weighted signal-to-noise ratio measures for rating the privacy of meeting rooms and a new measurement procedure has been developed to assess conditions close to the outside boundaries of a meeting room. While much progress has been made, further work is still required. For example, it is now clear that in many situations, privacy is significantly influenced by both signal-to-noise and reverberation in the rooms. Both factors must be included when assessing the privacy of situations with significant amounts of reverberation.