Vibrotactile Identification of Signal-Processed Sounds from Environmental Events Presented by a Portable Vibrator: A Laboratory Study

Objectives: To evaluate different signal-processing algorithms for tactile identification of environmental sounds in a monitoring aid for the deafblind. Two men and three women, sensorineurally deaf or profoundly hearing impaired with experience of vibratory experiments, age ۲۲-۳۶ years. Methods: A closed set of ۴۵ representative environmental sounds were processed using two transposing (TRHA, TR۱/۳) and three modulating algorithms (AM, AMFM, AMMC) and presented as tactile stimuli using a portable vibrator in three experiments. The algorithms TRHA, TR۱/۳, AMFM and AMMC had two alternatives (with and without adaption to vibratory thresholds). In Exp. ۱, the sounds were preprocessed and directly fed to the vibrator. In Exp. ۲ and ۳, the sounds were presented in an acoustic test room, without or with background noise (SNR=+۵ dB), and processed in real time. Results: In Exp. ۱, Algorithm AMFM and AMFM(A) consistently had the lowest identification scores, and were thus excluded in Exp. ۲ and ۳. TRHA, AM, AMMC, and AMMC(A) showed comparable identification scores (۳۰%-۴۲%) and the addition of noise did not deteriorate the performance. Discussion: Algorithm TRHA, AM, AMMC, and AMMC(A) showed good performance in all three experiments and were robust in noise they can therefore be used in further testing in real environments.

کلیدواژه ها:

Environmental sound ، Identification ، Narrow-band ، Tactile perception ، Transposing ، Vibration