These are frequencies less than 20 Hz (cycles per second) which represent sounds that most of us cannot hear. More information is available on the wikipedia article about infrasound.
The ration of a frequency to its total frequency is called relative frequency.
frequency meter is used to measure the frequency of unknown frequency signal.
The frequency in a frequency table is the number of occurrences within each class width. The total frequency is the sum of all frequency's within all the classes.
Period = 1 / frequency
Given a frequency table,the first cumulative frequency is the same as the first frequency;the second cumulative frequency is the sum of the first cumulative frequency and the second [ordinary] frequency;the third cumulative frequency is the sum of the second cumulative frequency and the third [ordinary] frequency;and so on.An alternative definition is that the cumulative frequency for any value is the sum of all the frequencies less than or equal to that value.
infrasonic
Infrasonic.
The definition of infrasonic is relating to sound waves with a frequency below the limit of human hearing, 20 Hz. Ultrasonic relates to sound waves with a frequency above the limit of human hearing, 20,000 Hz.
Human ears can hear frequencies between about 20 and 20,000 Hz, so anything below 20 is infrasonic, and anything above 20,000 Hz (20 kHz) is ultrasonic.
Infrasonic.'Subsonic' and 'infrasonic' both define sound too low (in frequency or pitch) to be heard by humans without assistance.However, as 'subsonic' can also mean something traveling slower than the speed of sound, and 'infrasonic' only means frequencies below the audible range, 'infrasonic' is the better answer.
Infrasonic denotes any sound that is at a frequency below the human capability of hearing, this is around 5-25Hz. Ultrasonic on the other hand is, conversely, a frequency that is above the human hearing range (over 20,000Hz).
A infrasonic sound has a frequency - under 20 kHz. See the link below.
Any frequency that is lower than those that humans can hear - that is, lower than about 20 Hz.
Animals that can hear infrasonic sounds are; frogs snakes ants dogs fishes whales beetles pigeons Usally, small animals can hear infrasonic sounds because they catches low frequency sound which is less than 20 Hz, especially insects. You may have observed that even if you walk very softly on the floor, animals like dogs feels your coming because they can hear infrasonic sounds.
ultrasonic means their frequency is too high for us to hear, infrasonic means their frequency is too low for us to hear. This is analogous to the electromagnetic spectrum, where ultraviolet light has too high a frequency for us to see, and infra-red light has too low a frequency for us to see.
The human ear cannot detect all possible frequencies. It has evolved to detect frequencies of sounds that are the most useful to humans, and has a maximum frequency range of about 20Hz to 20kHz, which decreases as you get older, particularly at the higher end. Infrasonic describes sounds that are too low in frequency to be heard by the human ear, and ultrasonic describes sounds that are too high in frequency to be heard by the human ear. These sounds cannot be heard by the human ear because they are outside of its range of capability.
For the human ear, sound is audible in the range of 20 Hz (Hertz) to 20000 Hz. Sounds below 20 Hz are "infrasonic" and have too low a frequency to be heard; sounds above 20000 Hz are "ultrasonic" and are too high a frequency to be heard.