No, the amplitude of a sound wave does not change if its frequency decreases. The amplitude of a sound wave refers to the maximum displacement or distance of the particles in the medium from their equilibrium position as the wave passes through. It represents the intensity or strength of the sound wave.
Frequency, on the other hand, refers to the number of complete cycles or vibrations of the sound wave that occur in one second. It is measured in hertz (Hz).
The amplitude and frequency of a sound wave are independent of each other. Changing the frequency of a sound wave does not directly affect its amplitude. The amplitude of a sound wave can be altered separately, for example, by changing the energy or force with which the sound is produced.
However, it's worth noting that changes in frequency can indirectly influence our perception of the sound's loudness. The human ear is more sensitive to certain frequencies than others. For example, our ears are generally more sensitive to sounds in the mid-frequency range (around 2 kHz to 5 kHz) compared to very low or very high frequencies. So, if the frequency of a sound decreases and enters a range to which our ears are less sensitive, the sound may appear quieter even if its amplitude remains the same.