Vehicle notification device, vehicle notification method, and storage medium

A vehicle notification device comprising:

• a sound generation device mounted on a host vehicle;
• and
• a controller that controls the sound generation device, wherein the controller is configured to
• acquire an environmental sound in a vehicle cabin of the host vehicle, via a vehicle cabin microphone that converts sounds in the vehicle cabin into electric signals,
• perform waveform analysis including frequency analysis of the acquired environmental sound and acquire a frequency band and a sound pressure of the environmental sound,
• determine a frequency band and a sound pressure of a notification sound based on the acquired frequency band and the acquired sound pressure of the acquired environmental sound by referring to a lookup table in which a plurality of frequency bands and a plurality of sound pressures of environmental sounds, and corresponding frequency bands and sounds pressures of notification sounds that are audible and unobtrusive to an occupant, are stored in association with each other, and
• execute a notification operation to notify an occupant of the host vehicle that the host vehicle is in a predetermined state by causing the sound generation device to generate a notification sound in the determined frequency band and the determined sound pressure.