5
Alternatively, the signal could be embedded on the audio system’s sound chip. However, due to
minor differences in software implementation, users must verify that the embedded test signal is
compatible with the meter being used. Verification can be obtained from the audio system
manufacturer.
STI measurements can be made without significant training. Once the STI-PA signal has been
input to the system under test, a single button push on the DSP2B/BP will produce the STI,
which can be converted CIS as specified in IEC standard 60849. The test only requires about 15
seconds. The STI-PA signal can be left continuously playing, making it possible to simply move
the DSP2B/BP to a new position and initiate a new measurement.
“VALIDATION: The DSP2B is designed for making STI (IEC 60268-16) and CIS
measurements and has been validated for that purpose by the TNO Human Factors Group.
Model DSP2BP is capable of making PRIVACY measurements in addition to intelligibility.
The TNO Human Factors Group recommends STI-PA as the preferred objective
methodology for measuring reproduced speech intelligibility.”
TECHNICAL PAPERS & DATA FOR FIRE AND HEALTHCARE
Emergency Communications Issues
See
http://www.gold-line.com/pdf/articles/p_sti01e14.pdf
Ken Jacob, presentation to the National Fire Protection Association Congress, Understanding
Speech Intelligibility and the Fire Alarm Code
.
NFPA 72, National Fire Alarm and Signaling Code (NFPA, Batterymarch Park, Quincy, MA)
uses the term Emergency Communications System (ECS) to describe emergency audio systems.
Subcategories include Emergency Voice Alarm Communications Systems (EVACS) used for
fire alarm voice announcements and Mass Notification Systems (MNS) used all emergency
signaling. Where the system being tested is an ECS, users should consult NFPA 72 for
requirements such as drawings, minimum sound levels for alert tones, designation and
identification of Acoustically Distinguishable Spaces (ADSs) and other requirements that might
affect a comprehensive measurement/test protocol.
Healthcare Issues:
Increasingly Codes and liability laws are compelling modern consultants, to find a way to verify
the Privacy of a system. The new HIPAA standards for Patient Information privacy is driving the
trend towards Privacy Index measurements as the best method for assuring that masking systems
are in fact providing adequate levels of privacy.
White papers
from Government Studies have
recommended
PI
as the preferred method for assuring that speech remains confidential. Two
recent studies by Dr. Kenneth Roy, PhD have documented the superiority of Privacy Index
measurements, and the legal issues related to failure to provide speech privacy under the new
HIPAA medical regulations see:
http://www.wedi.org/cmsUploads/pdfUpload/WhitePaper/pub/P-Final-Oral_Com.pdf
http://www.wedi.org/cmsUploads/pdfUpload/eventsPresentationInformation/pub/Milleran
dSykes.pdf
