New design methods for educating designers are needed to adapt the attributes of haptic interaction to fit the embodied experience of the users. This paper presents educationally framed aesthetic sensitizing labs: 1) a material-lab exploring the tactile and haptic structures of materials, 2) a vibrotactile-lab exploring actuators directly on the body and 3) a combined materials- and vibrotactile-lab embedded in materials. These labs were integrated in a design course that supports a non-linear design process for embodied explorative and experimental activities that feed into an emerging gestalt. A co-design process was developed in collaboration with researchers and users who developed positioning and communications systems for people with deafblindness. Conclusion: the labs helped to discern attributes of haptic interactions which supported designing scenarios and prototypes showing novel ways to understand and shape haptic interaction.

The goal of the present study was to compare six transposing signal-processing algorithms based on different principles (Fourier-based and modulation based), and to choose the algorithm that best enables identification of environmental sounds, i.e. improves the ability to monitor events in the surroundings. Ten children (12-15 years) and 10 adults (21-33 years) with normal hearing listened to 45 representative environmental (events) sounds processed using the six algorithms, and identified them in three different listening experiments involving an increasing degree of experience. The sounds were selected based on their importance for normal hearing and deaf-blind subjects. Results showed that the algorithm based on transposition of 1/3 octaves (fixed frequencies) with large bandwidth was better (p<0.015) than algorithms based on modulation. There was also a significant effect of experience (p<0.001). Adults were significantly (p<0.05) better than children for two algorithms. No clear gender difference was observed. It is concluded that the algorithm based on transposition with large bandwidth and fixed frequencies is the most promising for development of hearing aids to monitor environmental sounds.

Abstract-This study compared three different signal-processing principles (eight basic algorithms)-transposing, modulating, and filtering-to find the principle(s)/algorithm(s) that resulted in the best tactile identification of environmental sounds. The subjects were 19 volunteers (9 female/10 male) who were between 18 and 50 years old and profoundly hearing impaired. We processed sounds produced by 45 representative environmental events with the different algorithms and presented them to subjects as tactile stimuli using a wide-band stationary vibrator. We compared eight algorithms based on the three principles (one unprocessed, as reference). The subjects identified the stimuli by choosing among 10 alternatives drawn from the 45 events. We found that algorithm and subject were significant factors affecting the results (repeated measures analysis of variance, p < 0.001). We also found large differences between individuals regarding which algorithm was best. The test-retest variability was small (mean +/-95% confidence interval = 8 +/-3 percentage units), and no correlation was noted between identification score and individual vibratory thresholds. One transposing algorithm and two modulating algorithms led to significantly better results than did the unprocessed signals (p < 0.05). Thus, the two principles of transposing and modulating were appropriate, whereas filtering was unsuccessful. In future work, the two transposing algorithms and the modulating algorithm will be used in tests with a portable vibrator for people with dual sensory impairment (hearing and vision).

Monitor is a portable vibrotactile aid to improve the ability of people with severe hearing impairment or deafblindness to detect, identify, and recognize the direction of sound-producing events. It transforms and adapts sounds to the frequency sensitivity range of the skin. The aid was evaluated in the field. Four females (44–54 years) with Usher Syndrome I (three with tunnel vision and one with only light perception) tested the aid at home and in traffic in three different field studies: without Monitor, with Monitor with an omnidirectional microphone, and with Monitor with a directional microphone. The tests were video-documented, and the two field studies with Monitor were initiated after five weeks of training. The detection scores with omnidirectional and directional microphones were 100% for three participants and above 57% for one, both in their home and traffic environments. In the home environment the identification scores with the omnidirectional microphone were 70%–97% and 58%–95% with the directional microphone. The corresponding values in traffic were 29%–100% and 65%–100%, respectively. Their direction perception was improved to some extent by both microphones. Monitor improved the ability of people with deafblindness to detect, identify, and recognize the direction of events producing sounds.