Just noticeable difference of masker to enhance privacy in an open-plan office

If a background conversation (masker) is easy to follow, then a worker at a workstation in an open-plan office will be distracted and annoyed. The aim of this study was if the mixture of the background conversations statistical distribution close to Gaussianity, then regardless the loudness level, the intelligibility will be decreased. On the other hand, the privacy at the workstation will be increased due to the loudness level of the background conversation. To assess the privacy level in a simulated open-plan office, we propose Just Noticeable Difference (JND) of the masker. The measurement was conducted in two workstations laboratory with 64 square meters for each workstation in which three conditions (male-female, all male, and all female speakers) of babble noise was built in one of them. The other workstation was simulated with single speech sound to observe speech privacy in the presence of the masker. We used objective measures to assess the intelligibility and the privacy of the workstation. The results suggest that the saliency of the masker depends on the fundamental frequency difference (dominant speaker). The higher saliency of the masker will cause the lower of the privacy of the other workstation.