Providing speech privacy is an important goal in architectural acoustics. Studies beginning in the 1960s showed that concentrating only on sound isolation was not enough; speech effort, privacy expectations, and background noise levels were also essential considerations. A method was developed to help guide designers toward reasonably reliable results and simplified to accommodate non-technical input from laypersons, resulting in speech privacy worksheets. This led to further refinements and developments, such as for open-plan spaces, and by extension can help guide designs for non-speech sounds such as for music or equipment.
Hoover et al. (Tue,) studied this question.