Vehicle existence notification apparatus

Abstract

A vehicle existence notification apparatus, disposed in a vehicle, emits a notification sound to notify the surrounding area of the approach or presence of the vehicle. The vehicle existence notification apparatus includes a parametric speaker that serves as a supersonic speaker for emitting a supersonic sound wave, where the parametric speaker performs supersonic modulation to a notification sound signal, which produces the notification sound. The parametric speaker also serves as an audible-sound generating piezoelectric speaker that has a primary resonance component that vibrates at a frequency in an audible frequency band. The parametric speaker sets a supersonic modulation frequency of the notification sound to a sound-pressure increase frequency in a supersonic frequency band reproducible by the audible-sound generating piezoelectric speaker, at which a sound pressure increases due to a high order harmonic resonance.

Dependencies are inferred from the claim text.