Resonance tube of horn

A resonance tube of a horn mounted on a vehicle,

• the resonance tube comprising:
• a main resonance tube including an input opening surface to which a chord is input, the chord containing a first sound and a second sound, the first sound having a first frequency as a fundamental frequency, the second sound having a second frequency as a fundamental frequency, the second frequency constituting the chord together with the first frequency;
• and
• a branch resonance tube branching from the main resonance tube, wherein:
• one of the main resonance tube and the branch resonance tube serves as a first resonance tube that resonates with the first sound;
• the other of the main resonance tube and the branch resonance tube serves as a second resonance tube that resonates with the second sound;
• the first resonance tube includes a first opening surface from which the resonated first sound is output;
• the second resonance tube includes a second opening surface from which the resonated second sound is output;
• and
• the second opening surface is displaced from the first opening surface in a normal direction of the first opening surface.