If an intruder alarm is adjusted to give a quieter sound without affecting the pitch of the note, it means that the amplitude of the sound is being reduced while keeping the frequency or pitch unchanged.
Amplitude refers to the maximum displacement or intensity of a sound wave. It determines the loudness or volume of the sound. By reducing the amplitude of the sound, the overall intensity of the sound wave decreases, resulting in a quieter sound. This can be achieved by adjusting the settings or controls of the alarm to lower the output level or decrease the magnitude of the vibrations producing the sound.
On the other hand, frequency or pitch refers to the number of oscillations or cycles of the sound wave that occur per second. It determines whether the sound is perceived as high or low in pitch. When adjusting the alarm to produce a quieter sound without affecting the pitch, the frequency of the sound wave remains the same. The settings or controls of the alarm are adjusted only to reduce the amplitude while preserving the frequency.
In summary, when an intruder alarm is adjusted to give a quieter sound without affecting the pitch, the amplitude of the sound is reduced to lower the volume, while the frequency or pitch remains unchanged.