When you increase or decrease the amplitude of a sound wave while keeping the frequency constant, the wavelength of the wave remains the same. Amplitude and wavelength are independent of each other, meaning that changing one does not directly affect the other when the frequency is held constant.
Amplitude refers to the maximum displacement or intensity of the particles in a medium as the sound wave passes through it. It determines the loudness or intensity of the sound. By increasing the amplitude, you increase the maximum displacement of the particles and thus make the sound louder. Similarly, decreasing the amplitude reduces the maximum displacement and makes the sound quieter. However, these changes in amplitude do not alter the wavelength.
Wavelength, on the other hand, represents the distance between two consecutive points of a sound wave that are in phase, such as from one peak to the next or one trough to the next. It determines the pitch or frequency of the sound. The wavelength remains constant as long as the frequency is unchanged, regardless of the amplitude.
In summary, increasing or decreasing the amplitude of a sound wave while keeping the frequency constant does not affect the wavelength. The amplitude controls the loudness of the sound, while the wavelength is determined by the frequency and the characteristics of the medium through which the sound wave propagates.