def air_impedance(sound_speed: float, air_density: float) -> float:
    """Calculates the Characteristic Impedance of the Air.

    Args:
        sound_speed (float): Sound speed in the air [m/s].
        air_density (float): Air density [kg/(m^3)]

    Returns:
        float: Characteristic Impedance of the Air [Rayl]
    """
    return sound_speed * air_density