Provided are a program and a sound output device for maintaining the interest of the user. A sound output device 1 which outputs prescribed musical scales comprises: a level information acquisition unit 13 that acquires, as level information, a user's sense of pitch; a sound output unit 16 that outputs sound of which the pitch has been changed under prescribed conditions based on the acquired level information; a response information acquisition unit 19 that acquires, as response information, a response to the change in a musical scale input by the user on the basis of the output musical scale; a correctness determination unit 20 that determines the correctness of the acquired response information; and a level determination unit 21 that determines the level of the user's sense of pitch on the basis of the determination result.