ARDMS (American Registry for Diagnostic Medical Sonography) Practice Test

What is the fundamental frequency of a sound wave?

1. The highest frequency of a periodic waveform

2. The average frequency of a sound wave

3. The lowest frequency of a periodic waveform

4. The frequency that corresponds to the loudest sound

The correct answer is: The lowest frequency of a periodic waveform

The fundamental frequency of a sound wave refers specifically to the lowest frequency produced by a periodic waveform and is commonly associated with the primary tone or pitch perceived in music or acoustics. It represents the frequency at which the wave vibrates in its simplest form, serving as the foundation for the harmonic series. In acoustics, complex sounds can be made up of multiple frequencies, known as harmonics, but the fundamental frequency is the first harmonic at the lowest pitch. This concept is essential for understanding sound properties in both musical instruments and various diagnostic applications in medical sonography, where the fundamental frequency influences image quality and resolution. Other frequencies in a sound wave can be perceived as overtones, which are higher in pitch and are integer multiples of the fundamental frequency. While the highest frequency of a waveform and the loudest sound are relevant in different contexts, they do not define the fundamental frequency. The average frequency might suggest a broad measure, but it does not capture the specific importance of the lowest frequency in a periodic waveform.