What is frequency
Frequency is the number of oscillating (repeating) cycles per second and it is expressed in Hertz (abbreviated Hz). In simple words, if the signal completes one cycle per second, then it is considered as 1 Hz and the 20 Hz means that the signal or pulse completed 20 cycles per second.
Also, if the signal completed 1000 cycles per second it is represented as 1 kHz (Kilohertz) and if the signal completed 1,000,000 (1 million) cycles per second it is represented as 1 MHz (Megahertz). 1,000,000,000 (1 billion) cycles per second is 1 GHz (Gigahertz). 1 trillion cycles per second is considered as 1 THz(Terahertz).
The frequency which is audible to human is called as an Audio Frequency. Human has the hearing range from 20Hz to 20kHz and it changes according to the age of the human.
Animals have different hearing ranges, and it can also change according to the breed. The dog has 64 Hz to 44kHz hearing range.
What is Radio Frequency
Frequencies which are easily transmitted through the air are called as Radio Frequencies. In theoretical, the radio frequency emitted by the electromagnetic wave spectrum or the frequency of electromagnetic waves which oscillates between 6 kHz to 300 GHz.
Using antennas and transmitters, RF fields can be used for different types of broadcasting and wireless communication.
High-frequency hearing loss
The hearing loss (auditory impairment) resulting from the aging process is called presbycusis. Since this is a slow process that usually affects both eyelashes equally, it is often difficult to notice.
People suffering from high-frequency hearing loss have problems in the range of 2,000-8,000 Hertz (Hz). In the speech, this includes consonants such as f, h, or s.