No abstract

During push switch operation, tactile feedback is crucial in determining whether the operation will be successful. However, to enhance the tactile feedback and ensure usability, the actuation force should not increase. Herein, a method to improve tactile feedback during switch operation by designing the operating sound is proposed. In the first experiment, to investigate the acoustic characteristics of high feedback operating sound, participants evaluated recorded commercial push switch operating sounds through headphones using the semantic differential method. Results showed that the operating sound with a short decay time and high loudness value in the highfrequency band exhibited a highly intelligible impression. Furthermore, the push switch operation exhibited two sounds (push and release), whose contribution to the impression was determined based on their loudness. In the second experiment, participants evaluated their impressions when operating push switches, which comprised various combinations of operating sound volume and actuation force. Results showed that highly intelligible sound improved the tactile feedback. Moreover, it was found that considering the balance between the operating sound volume and actuation force is necessary to improve the switch operation feedback through the operating sound. These findings can aid in enhancing the feedback of devices that require switches with low actuation force due to design constraints.

No abstract

To investigate the performance of horizontal sound localization of elderly people, authors conducted a test using 19 elderly participants (10 males, 9 females; ages 65-85; mean 71.5 years old.) The stimuli were presented through headphones to their right and left ears with 4 interaural time differences (ITDs) (0.2, 0.4, 0.6, and 0.8 ms) and 4 interaural level differences (ILDs) (3, 6, 9, and 12 dB(A)) besides the same condition to both ears. Concerning the frequency, pure tones of 1.0 and 2.0 kHz, and composite sound of 0.5 + 2.0 kHz were presented, which lasted one second for each trial. The participants answered “Right” or “Left” after each trial according to their own judgment. The results of ITD condition showed that in case of the pure tones a right-sided inferiority was recognized, which was poorer than the results of the younger participants. Meanwhile, no right/left difference was recognized with the composite sound. Concerning the ILD condition, no right/left asymmetricity was shown. Furthermore, no significant differences were recognized regarding the relationships between their sound localization performance and potential influential factors. The factors were Trail Making Test (TMT) results, their preferred ear, and their hearing loss difference between right/left ears.

To investigate the performance of horizontal sound localization of younger people, authors conducted a test using 12 young participants (11 males, 1 females; ages 21–24.) The stimuli were presented through headphones to their right and left ears with 4 interaural time differences (ITDs) (0.2, 0.4, 0.6, and 0.8 ms) and 4 interaural level differences (ILDs) (3, 6, 9, and 12 dB(A)) besides the same condition to both ears. Concerning the frequency, pure tones of 0.5, 1.0, and 2.0 kHz, and composite sound of 0.5 + 2.0 kHz were presented, which lasted one second for each trial. The participants answered “Right” or “Left” after each trial according to their own judgment. The results of ITD condition showed that a right-sided inferiority was recognized in case of 1.0 and 2.0 kHz. Concerning the ILD condition, no right/left asymmetricity was shown. This asymmetricity may be caused by the improper setting of the experiment apparatus. Therefore, we switched right/left of the headphones to carry out an additional test in the same way. The same tendency as the original test was obtained, which means that the asymmetricity is likely due to the native characteristics of the participants.