Explanation:

- Sound waves above 20,000 cycles per second (cps) are beyond the audible range for humans.

- Ultrasonic:

- These waves exceed 20,000 cps.

- Utilized in medical imaging and cleaning devices.

- Often used by animals such as bats for navigation.

- Correct Answer

- Supersonic:

- Refers to speeds greater than the speed of sound in air.

- Not related to frequency or cps.

- Overtones:

- Higher frequency waves produced in musical instruments.

- Referential to harmonic frequencies, not exceeding audible range.

- Infrasonic:

- Frequencies below 20 cps.

- Used in monitoring natural events like earthquakes.