Information transmission apparatus

An information transmission apparatus configured to be provided on a vehicle that includes a steering device configured to steer a wheel includes a parameter detector, a vibrator, a rotation center calculator, and a gain adjuster. The parameter detector is configured to detect a parameter σ that correlates with a steering amount of the steering device. The vibrator is configured to vibrate air around an occupant based on a predetermined vibration waveform in accordance with a change in the parameter of the steering device. The rotation center calculator is configured to calculate a position of a rotation center of a yaw behavior of a body of the vehicle. The gain adjuster is configured to adjust an output gain of the vibration waveform in accordance with a relative position between the rotation center and a seating position of the occupant.