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Perspectives on Designing Human Interfaces for Automated Systems
Published in Richard L. Shell, Ernest L. Hall, Handbook of Industrial Automation, 2000
Anil Mital, Arunkumar Pennathur
Sound localization is the ability to determine and localize the direction of the sound. The differences in the intensity of sounds, and the differences in the phase of sounds are the primary measures by which the human auditory system determines the direction of the sound source. It has been shown that for frequencies below 1500 Hz, if the source of the auditory signal is directly to one side of the head, the signal reaches the nearer ear approximately 0.8 msec before it reaches the other ear. Also, localization is difficult at low frequencies, since there is very little difference in the time it takes for the signal to reach both ears simultaneously. However, at high frequencies (generally above 3000 Hz), the presence of the head between the ears makes intensity differences more pronounced resulting in effective localization of the sound source.
Hearing, Proprioception, and the Chemical Senses
Published in Robert W. Proctor, Van Zandt Trisha, Human Factors in Simple and Complex Systems, 2018
Robert W. Proctor, Van Zandt Trisha
Accurate sound localization depends on having two ears. There are two different sources of information: interaural intensity differences and interaural time differences, which are analyzed by different neural mechanisms (Marsalek & Kofranek, 2004). The relative intensity at each ear varies systematically as the location of a sound is moved from front to back. When the sound is at the front of the listener, the intensity at each ear is the same. As the location changes progressively toward the right side, the intensity at the right ear relative to the left increases, with the difference reaching a maximum when the sound is directly to the right. As the location is moved behind the listener, the difference shifts back toward zero.
Assistive technologies for severe and profound hearing loss: Beyond hearing aids and implants
Published in Assistive Technology, 2020
Setia Hermawati, Katerina Pieri
Environmental sounds provide important information about occurring events and the current condition of our surroundings. However, people with severe to profound hearing loss are unable to perceive and localise them. A number of studies have attempted to address this by providing wearable devices that can help deaf people with environmental sound detection and localisation (Daoud, Al-Ashi, Abawi, & Khalifeh, 2015; Gorman, 2014; Kim, Choi, & Kim, 2014; Matsuda, Nakamura, & Sugaya, 2014). Some of the ATs necessitated the use of smart glasses equipped with microphones arrays and light emitting diodes (Gorman, 2014; Kim et al., 2014), a belt that contains microphone arrays and delivers haptic feedback (Daoud et al., 2015), or simply wearable microphones (Matsuda et al., 2014). The evaluation of the devices’ technical performance showed that much work is still needed due to the low accuracy and response time of sound localisation.
Tuning in: can humans use auditory cues for spatial reorientation?
Published in Spatial Cognition & Computation, 2020
Daniele Nardi, Alexandra D. Twyman, Mark P. Holden, Josie M. Clark
Auditory information can be used to guide reorientation, but compared to visual cues, participants were far less accurate. In a recent visual-based reorientation study designed to investigate integration of a geometric and a feature cue, participants displayed very small errors (Twyman, Holden & Newcombe, 2018). The task was very similar to the present study: participants started facing a certain direction, were disoriented, and then had to return to the original facing direction. Furthermore, the search space was a continuous circle surrounding the participant; thus, responses could be distributed around 360°, which is quite unique for reorientation tasks. Findings indicated that, just like in our task, participants could use each cue individually, but the responses were much more accurate (within 1° of error) for Twyman et al. (2018) compared to the present study, where the lowest average absolute error was 60° (in the third training trial). Thus, people appear to be more accurate in reorientation with visual access to the environment compared to auditory access. This is expected, given that even simple localization of auditory sources normally yields greater errors than visual localization (Blauert, 1997). The extent of uncertainty in sound localization is also increased in reverberant environments, where sounds are reflected on objects and walls (Blauert, 1997). Using the same experimental apparatus and room as the present study, in Nardi et al. (2018) participants were tested for sound localization by placing the hairclip on the circumference in the direction of the sound source. The average localization error was 9.4°, which is similar to the average that has been reported in other studies (approximately 7°; Blauert, 1997). It is plausible that the greater uncertainty localizing sounds, and the lower accuracy in auditory-guided reorientation, might be related to – and perhaps be a cause of – the difficulty in spontaneously adopting this strategy. Future studies need to systematically examine the reorientation error with different types of auditory stimuli, varying the salience and the number of cues. It should be noted that reorientation guided by another nonvisual cue, slope, also yields relatively large absolute errors (an average of 59° was observed in Nardi et al., 2018), and is also associated with difficulty in spontaneous encoding of the cue (Nardi et al., 2011).