What is it called when sound frequencies exceed 20,000 Hertz?

When sound frequencies exceed 20,000 Hertz, the term used to describe these sounds is "ultrasonic." This classification is important in the study of sound waves, as it denotes frequencies that are above the normal range of human hearing. Humans typically hear sounds in the frequency range of 20 Hz to 20,000 Hz, so sounds above 20,000 Hz are not perceivable by the human ear.

Ultrasonic sounds are utilized in various applications, including medical imaging (such as ultrasound scans), industrial cleaning, and pest control, among others. The technology that leverages these high frequencies often capitalizes on their ability to travel through different media, making them valuable in practical applications.

While options like "ultrasound wave" refer to a specific application of ultrasonic frequencies (especially in medical imaging), the generic term for any sound frequency exceeding 20,000 Hertz is "ultrasonic." The other choices, such as "high frequency," lack the specific definition needed to accurately describe the frequency range being referred to, and thus do not provide the precision that "ultrasonic" does.