Article
Evaluation of Local Acoustical Privacy Protection in Small, Enclosed Compartments (en)
* Presenting author
Abstract:
Acoustic communication in small, enclosed compartments exhibits a challenge to establish private spheres for single users without heavily affecting the acoustical surrounding for other persons. For a use-case in car compartments a recently developed privacy protection approach was examined within a listening test. Ensuring control over several conditions of the experimental setting while providing the listeners a comfortable situation simulating real-world conditions, a specific real-time capable setup in an anechoic room was used. Different positions for speaker and would-be listener were examined under multiple driving conditions. Signal-dependent spectral and spatial auditory masking via broadband noise and temporal distractors were adjustable components of the evaluated approach. Initially the level of the broadband component was adjusted individually to guarantee unintelligibility. However, since they cause the most affecting loudness increase, these levels provided anchors to start an individual adaptive adjustment procedure. Subjects presented with masked spoken sentences would echo the recognized parts immediately. Their responses were evaluated by an automatic speech recognition system in real-time to guarantee sufficient masking. Within this procedure the broadband noise levels were readjusted by additionally applying temporal compact distractors in order to prevent global and local loudness increase in the car interior.