Proposal of External-Ear Model-Based Mobile Device for Hazard-Sound Detection

Hazardous sounds can signal danger and should be heard to ensure safety. Hearing-impaired people can get into accidents due to the difficulty of hearing hazardous sounds. Therefore, the hearing-impaired people live with hearing-assistance dogs. However, the number of such dogs has decreased recently, and they have become less known in society and they may even be prevented from entering public facilities such as restaurants. Therefore, the external ear model-based mobile device for hazard-sound detection that can detect hazardous sounds and alert the hearing-impaired people are proposed. In this paper, the external ear model-based mobile device for hazard-sound detection is proposed and effectiveness of the external attachment for the microphone sensor is evaluated. Four different microphone sensors are used, and the spectral envelopes of each recorded sound are compared. The vowel /a/ and the ambulance siren are used as test sounds. The results show that using an external attachment modeled after an animal ear makes it easier to detect formants, which are frequency characteristics of sound. This is due to two effects: the sound collection effect of pinna's attachment and resonance in ear canal's attachment.