A new system of speech privacy criteria in terms of Speech Privacy Class (SPC) values

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ConferenceProceedings of 20th International Congress on Acoustics, ICA 2010: 23 August 2010, Sydney, Australia
Pages15; # of pages: 5
SubjectSpeech privacy, speech security, criteria for speech privacy; Office acoustics; Speech security
AbstractThis paper describes a new system` of speech privacy criteria in terms of Speech Privacy Class (SPC) values. SPC values can be used to specify the required speech privacy for new construction or to assess the speech privacy of ex-isting closed rooms. The ASTM E2638 measurement standard defines SPC as the sum of the measured average noise level at the position of a potential eavesdropper outside the room, and the measured average level difference between a source room average and the transmitted levels at the same potential eavesdropper location. For a given combination of level difference and ambient noise level, the likelihood of transmitted speech being audible or intelligible can be related to the probability of higher speech levels occurring in the meeting room, based on the statistics of speech levels from a large number of meetings. For a particular meeting room speech level, there is an SPC value for which transmitted speech would be at the threshold of intelligibility or even at the threshold of audibility. One can create a set of increasing SPC values corresponding to increasing speech privacy and for each SPC value one can give the probability of transmitted speech being either audible or intelligible. This makes it possible to accurately specify speech privacy criteria for meeting rooms and offices, varying from conditions of quite minimal to extremely high speech privacy, with an associated risk of a speech privacy lapse which is acceptable for each situation.
Publication date
AffiliationNRC Institute for Research in Construction; National Research Council Canada
Peer reviewedYes
NRC number54472
NPARC number20374320
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Record identifiercf69d165-7fb1-46c9-b60f-e6c8020b0c11
Record created2012-07-23
Record modified2016-05-09
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