Investigation of user complaints of sound masking delivered from underfloor air distribution grilles.

A LEED‐Gold certified government building includes six floors of open‐plan office space that are equipped with electronic sound masking delivered from a raised floor having under‐floor air distribution (UFAD). Results of user polling show mixed results for acoustic satisfaction, with significant complaints about speech privacy, and noise from the systems interfering with users’ ability to work. This research focuses on this dissatisfaction, the general conflict between speech privacy ease of verbal communication, and acceptance of noise‐generating treatments. Little research has been done on masking delivered via UFAD, so it was also desired to further the understanding of this design as part of a larger research program by the Federal government on Green Buildings. Specific objectives were to develop and test possible remedies for this system, and improve planning of future facilities that may have masking via UFAD. On‐site measurements of masking and HVAC spectra, as well as noise reduction and observations for various conditions, were made. Post‐measurement data analysis was conducted, and experimental remedies were developed and tested. The results and recommendations will be presented.