Convention Paper
New Techniques for Measuring Speech Privacy & Efficiency of Sound Masking Systems
AES Convention 122 · Paper 7126 · May 2007
Abstract
Speech privacy is becoming an increasingly important aspect for many workplace and security environments as well as hospital and medical centres where patient confidentially is of critical importance. Traditionally, Speech privacy has been measured by means of the Articulation Index, transposed to rate privacy rather than intelligibility (PI=1-AI). However, this is an indirect and cumbersome method that usually requires a spreadsheet calculation to yield the Privacy Index rating. The paper discusses the potential use of STI and STIPa as direct measures of speech privacy. The benefits and limitations of the methods are highlighted together with the results from a number of case studies. It is concluded that whilst the method has potential merit, a number of the limiting factors require further research.
