When you increase the amplitude of a sound wave by doubling it, without changing any other factors such as wavelength or speed of propagation in the air medium, several effects can occur:
Increased Loudness: The amplitude of a sound wave is directly related to its perceived loudness. By doubling the amplitude, the sound will generally be perceived as louder. This is because an increase in amplitude corresponds to an increase in the pressure variations caused by the sound wave, resulting in a more intense auditory sensation.
Higher Energy: Increasing the amplitude of a sound wave increases its energy. The energy of a sound wave is proportional to the square of its amplitude. Thus, doubling the amplitude will quadruple the energy of the sound wave.
Greater Sound Pressure: The sound pressure level (SPL) of a sound wave is directly related to its amplitude. SPL measures the magnitude of the pressure variations caused by the sound wave. By doubling the amplitude, the sound wave will generate higher maximum and minimum pressure values, resulting in a greater sound pressure level.
Unchanged Frequency and Wavelength: Increasing the amplitude of a sound wave while keeping the wavelength and speed of propagation constant does not affect the frequency or wavelength of the wave. The frequency determines the pitch of the sound and remains the same regardless of the amplitude changes.
It's important to note that doubling the amplitude of a sound wave can have practical limitations. If the amplitude becomes too large, the sound wave may reach the limits of the medium's capacity to transmit it faithfully, resulting in distortion or nonlinear effects.