Final answer:
Adjusting the power knob to a higher level on an ultrasonic device affects the amplitude of the sound waves, which correlates to the loudness of the sound.
Step-by-step explanation:
When you adjust the power knob on an ultrasonic device to a higher level, you affect the amplitude of the sound waves. The amplitude is related to the loudness or intensity of the sound. Higher amplitude means a more powerful wave and therefore louder sound.
In context with other properties of sound, increasing the amplitude of a wave will increase the loudness, while increasing the frequency will increase the pitch. The wavelength is inversely proportional to the frequency and is determined by the speed of sound in the medium and the frequency. However, the phase relates to the position of the wave in its cycle at a given point in time and is not affected by amplitude adjustments.
For reference within wave phenomena, the Doppler effect induces a change in frequency perceived by an observer moving relative to the sound source, and a sonic boom occurs when an object moves faster than the speed of sound, related to the object's speed and not its frequency or amplitude.