CPC H04R 3/04 (2013.01) [B60Q 5/008 (2013.01); H04R 1/2803 (2013.01); H04R 2499/15 (2013.01)] | 9 Claims |
1. A sound output device comprising:
a waveform output unit configured to
acquire information relative to a traveling state of a vehicle from an external sensor,
determine whether the vehicle is traveling at a speed lower than a predetermined speed based on the information relative to the traveling state,
in response to determining that the vehicle is traveling at the speed lower than the predetermined speed, determine a center frequency within an audible frequency band according to a frequency band in which a sound pressure is desired to be output as a notification sound for notifying approach of the vehicle, set a first waveform having the center frequency, widen a frequency of the first waveform by a frequency modulation to generate a second waveform having a frequency within the audible frequency band, and output a sound data indicating a sound waveform including the second waveform; and
a sounding body configured to receive a voltage or a current corresponding to the sound data, and generate a sound corresponding to the voltage or the current as the notification sound.
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