Development of residential fire alarm sound transmission system for the elderly with hearing loss

Abstract

In this paper, the authors proposed a system for sending fire alarm information to the elderly with hearing loss. This system consists of following five elements: (1) electret condenser microphone for measuring a sound, (2) sound signal detection circuit for extracting only a fire alarm signal, (3) voltage frequency conversion circuit, (4) direct current voltage conversion circuit, and (5) vibration unit. If a fire alarm is generated, it was confirmed that the vibration unit was driven only when the fire alarm sounded. Next, the authors compared the perception time the sound of the fire alarm and the vibration of the vibration unit. Assuming bedtime, the vibration unit was installed under the pillow. The experiment was carried out in a room of 25.8m³. The subject placed in supine position, and attached ear plug and eye mask. By the alarm sound or vibration，the subject was stimulated at random at intervals of 30 seconds five times in three types of pillows. As a result of the comparison experiment, it was found that vibration has a shorter perception time than alarm sound. Furthermore, as a result of the one-way analysis of variance, the p value was less than 0.01. Therefore, made multiple comparisons, the significant difference of 5% of the significance level was observed between alarm and vibration.