| Answer | Crossword Clue |
|---|---|
| SONIC | Within audible frequencies |
| infrasound | frequencies below the usual audible limit |
| infrasounds | INFRASOUND, frequencies below the usual audible limit |
| midrange | The middle part of the range of audible frequencies |
| ultrasonic | denoting air-waves or vibrations with frequencies higher than those audible to the human ear |
| ultrasonically | ULTRASONIC, denoting air-waves or vibrations with frequencies higher than those audible to the human ear |
| audio | of or relating to acoustic, mechanical, or electrical frequencies corresponding to normally audible sound waves which are of frequencies approximately from 15 to 20,000 hertz |
