- Modern tubes approach that ideal by drawing power at such high frequencies - tens of kilohertz - that the x-ray output is steady apart from a ripple of a few percent.
- Most bats emit sonar at ultrasonic frequencies around 20-60 kilohertz (humans hear up to 20 kHz), and this is the range at which hearing moths are most sensitive!
- By comparison, a typical AM radio station operates in the kilohertz range, or thousands of cycles per second.
- Another curious aspect to leopard seal vocalizations is their use of high-pitched clicks up to 165 kilohertz, a frequency far beyond the range of normal human hearing.
- The sonar that will be used has a frequency of 170 kilohertz and is considered safe for the animals.