Hearing range 60 decibels, the hearing range for the Senegal bushbaby is 92 Hz–65 kHz, and 67 Hz–58 kHz for the ring-tailed lemur. Of 19 primates tested, the Japanese macaque had the widest range, 28 Hz–34.5 kHz, compared with 31 Hz–17.6 kHz for humans. Cats have excellent hearing and can detect an extremely broad range of frequencies. They can hear higher-pitched sounds than humans or most dogs, detecting frequencies from 55 Hz up to 79 kHz. Cats do not use this ability to hear ultrasound for communication but it is probably important in hunting, since many species of rodents make ultrasonic calls.
CB usage in the United States types of diathermy machines commonly operate in this range. These devices centered on 27.12 MHz with a tolerance of ±163 kHz, that is, 26.957 to 27.283 MHz. The Business Radio Service has several channels just above the Citizen's Band, at 27.430, 27.450, 27.470, 27.490, 27.510, and 27.530 MHz. The federal government has the frequencies from 27.540 up to 28.000. Many civilian agencies use, or used to use, the frequencies 27.575 and 27.585 for low-power use. These frequencies are often used by illegal operators using modified CB or amateur radio equipment. The 10 meter amateur radio (ham) band runs from 28.000