Akio Honda

EMPATHY, SPATIAL AND VERBAL ABILITIES CHARACTERIZE ONE WHO CAN BEST DESCRIBE A ROUTE','

We investigated the characteristics of people who provided the most intelligible description of a route. 18 participants were asked to describe the route on their own campus. Then, participants completed the Japanese Wechsler Adults Intelligence Scale-Revised and the Interpersonal Reactivity Index. Subsequently, 72 raters (36 university students who were familiar with the environment and 36 students who were unfamiliar) were asked to read and rate each of the 18 descriptions on a 7-potnt scale based on intelligibility of the verbal descriptions. Analysis indicated that a person who can provide the most intelligible description of the route has a higher empathic concern, which is necessary to consider intelligibility of the description to the addressees as well as higher spatial abilities, which are relevant to spatial representation of the route.

Eight Personal Characteristics Associated with the Power to Live with Disasters as Indicated by Survivors of the 2011 Great East Japan Earthquake Disaster

People perceive, judge, and behave differently in disasters and in a wide range of other difficult situations depending on their personal characteristics. The power to live, as captured by characteristics that are advantageous for survival in such situations, has thus far been modeled in arbitrary ways. Conceptualizing such characteristics in more objective ways may be helpful for systematic preparations for future disasters and life difficulties. Here, we attempted to identify the major factors of the power to live by summarizing the opinions of survivors of the 2011 Great East Japan Earthquake disaster. We conducted personal interviews with 78 survivors about their survival experiences and elicited their opinions about the power to live as relevant to those experiences. We then incorporated these opinions into a questionnaire that was completed by 1400 survivors. Factor analysis identified eight factors related to the power to live: leadership, problem solving, altruism, stubbornness, etiquette, emotional regulation, self-transcendence, and active well-being. All factors had sufficient internal construct validity, and six of them showed significant associations with one or more measures of survival success in the disaster, including immediate tsunami evacuation, problem solving in refugee situations, recovery during reconstruction, physical health, and mental health. Overall, the personal characteristics described by the eight factors largely overlap with those described in previous arbitrary models. Further research should investigate the domains, phases, and contexts in which each factor contributes to survival, address whether the factors are rooted in nature or in nurture, and explore their psychological or physiological bases.

Detection of Sound Image Movement During Horizontal Head Rotation

Movement detection for a virtual sound source was measured during the listener’s horizontal head rotation. Listeners were instructed to do head rotation at a given speed. A trial consisted of two intervals. During an interval, a virtual sound source was presented 60° to the right or left of the listener, who was instructed to rotate the head to face the sound image position. Then in one of a pair of intervals, the sound position was moved slightly in the middle of the rotation. Listeners were asked to judge the interval in a trial during which the sound stimuli moved. Results suggest that detection thresholds are higher when listeners do head rotation. Moreover, this effect was found to be independent of the rotation velocity.

Sound production shows robust loudness constancy when visual cues of musical performance are available

We examined the degree of loudness constancy using two methods of adjustment. One was “sound production,” by which listeners played a musical instrument as loudly as a model player. The other was “sound level adjustment,” by which listeners adjusted the loudness of the sound produced by a loudspeaker. The target sound was produced by the actual musical instrument performance. Sound pressure levels of the stimuli were approximately 60, 75, and 86 dB(A). The distances between the performer and the participant were 2, 8, and 32 m. In both conditions, participants were asked to produce the level of sound pressure matching the stimulus. Results show that when visual cues of musical performance are available, sound production had more robust loudness constancy than the sound level adjustment method.

Effects of listener’s whole-body rotation and sound duration on sound localization accuracy

Listeners head movement is known to facilitate sound localization, which creates dynamic changes to the information input to both ears. For this study, we used a digitally controlled spinning chair to examine the effects of a listener’s whole-body rotation and sound duration on sound localization accuracy. We measured their sound localization accuracy at locations from left 30 deg to right 30 deg with respect to the listener. Stimuli were 1/3-octave band noise burst (fc = 1 kHz, SPL = 65 dB) with duration of 50, 200, and 1000 ms. Each stimulus was presented from a loudspeaker in a circular array. The listener, sitting on the chair at the circle center, reported the position of the presented stimulus in chair-still (0 deg/s) and chair-rotation (10 deg/s) conditions. Results showed superior sound localization accuracy of chair-rotation condition to that of a chair-still condition. Moreover, a significant effect of sound duration was observed, but interaction of the test condition and the sound duration was...

Auditory space perception during self-motion

Spatial information inputted to the auditory periphery dramatically changes with a listener’s body movements relative to the sound source. Nevertheless, listeners can perceive a stable auditory environment and react appropriately to the sound source. This suggests that the spatial information is reinterpreted in the brain by being integrated with information regarding movement, while it is well known that the motion itself sometimes negatively affects sound localization acuity. We have focused on how people perceive auditory space during movement. A linear-motor-driven chair and a spinning chair were installed in an anechoic room to provide linear and rotatory motion, respectively. The results revealed that the perceived sound position during linear self-motion was displaced compared with the physical sound position. This displacement was observed regardless of the self-motion direction and the inputted sensory information which induces self-motion. Such degradation of sound localization acuity was also o...

Auditory guided adjustment shows robust loudness constancy

Perceptual constancy refers to a tendency to perceive an object as having a constant shape, size, and brightness despite apparent changes in these stimulus features. Few studies have systematically and critically examined loudness constancy. We use two adjustment methods to examine it in a natural environment: “auditory guided adjustment”, by which listeners play a musical instrument as loud as a model player; and “volume adjustment,” by which listeners adjust the loudness of the sound produced by a loudspeaker. The experiments were conducted in the Yamanashi Eiwa College gymnasium, where dark noise was 32-35 dB(A). Stimuli were 2-s musical sounds with G4 (393 Hz) pitch produced by the actual musical instrument performance. The distances separating the model performer and the participant were 2 m, 8 m, and 32 m. Sound pressure levels of the stimuli were set as small, medium, and large corresponding to 60, 75, and 86 dB(A). Participants were asked to produce the sound of the same loudness. It was found tha...

Effects of a listener’s very slow rotation on sound localization accuracy

A listener’s head movement is effectively used to accurately localize sounds. By contrast, when a sound stimulus is presented during head rotation, sound localization acuity decreases. Previous studies have shown that sound localization accuracy is degraded even during slow head rotation at 50/s. In this study, we investigated the sound localization accuracy during very slow head rotation from 0.6250/s to 50/s. We measured the detection thresholds (DTs) at the listener’s subjective front. The experiment consisted of static and rotation conditions. Listeners were asked to report whether a 30 ms noise burst was presented from the left or right of the subjective front (2 Alternative Forced Choice Task). In the results, the DTs in the rotation condition were larger than that in the static condition. Moreover, DTs seem almost independent of the rotation speed. This suggests that the sound localization resolution at the subjective front is degraded by a listeners passive rotation irrespective of the rotation s...

Minimum audible angle at the subjective front during listener’s head rotation

Sound localization is a multisensory process consisting not only of hearing, but also of self-motion perception. A large number of studies have shown that the listener’s head movement, particularly horizontal rotation, effectively improves sound localization acuity (Wallach, 1939; Thurlow, 1967; Kawaura, 1989; etc.). However, research into sound localization during head rotation is scarce. Thus, the multisensory process underlying sound localization remains unclear. In the present study, we directly investigated the minimum audible angle (MAA) — the detection threshold needed for the listener to localize sounds at different positions — at the front during horizontal head rotation. A sound stimulus (30-ms noise burst) was presented from a loudspeaker of a circular array (r = 1.1 m), with a loudspeaker separation of 2.5 degrees. The listener, sitting at the center of the circle, was asked to answer whether the sound stimulus was presented from the left or right of the subjective front (2AFC). We considered two listening conditions, static and dynamic. In the static condition, listeners were asked to keep their heads still. Meanwhile, for the dynamic condition, listeners were asked to rapidly rotate their heads; the test stimulus was triggered during head movement. Sound stimuli were presented from a randomly selected loudspeaker out of a subset of 13 centered at the listener’s physical front at the time of stimulus presentation. Results showed the MAA to deteriorate significantly in the dynamic condition. This implies that the improvements in sound localization due to head motion could be explained by the multiple-look model (Viemeister and Wakefield, 1991).

Minimum audible angle at the subjective front during listener’s active and passive head rotation

Listener’s head movement, particularly horizontal rotation, effectively improves sound localization acuity (Wallach, 1939; Thurlow, 1967; Kawaura, 1989). However, few findings have been obtained concerning sound localization during head rotation. In the present study, we directly investigated the minimum audible angle (MAA) at the front during horizontal rotation. A sound stimulus (30-ms noise burst) was presented from a loudspeaker of a circular array (r = 1.1 m), with a loudspeaker separation of 2.5 degrees. The listener, sitting at the center of the circle, was asked to answer whether the sound stimulus was presented from the left or right of the subjective front (2AFC). We designed three listening conditions, static, active rotation and passive rotation. In the static condition, listeners were asked to keep their heads still. For the active rotation condition, listeners were asked to rotate their heads. Meanwhile, for the passive rotation condition, listeners sitting on a revolving chair were rotated ...