Given a passage and a query based on the passage, generate an unambiguous, concise and simple answer to the query from information in the passage. Note that the answer may not be present in exact form.
Q: BBC ©️ 2014 The BBC is not responsible for the content of external sites. Read more. This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so. Frequency, wavelength, cycles, period all refer to the pitch of the sound and where they sit on the frequency spectrum. 1 Short wavelength = high frequency = faster cycles = higher pitch. 2 Long wavelength = low frequency = slower cycles = lower pitch. Sounds are heard by the ear as either being loud or soft. The loudness of a sound in measured in decibels. Decibels refer to the energy produced by that sound. A human can hear sounds ranging from 0.1 decibels, which is very soft, to sound which measure 120 decibels. Younger people can often hear lower volumes better than older people. The perception of loudness is related to sound pressure level (SPL), frequency content and duration of a sound. [citation needed] The relationship between SPL and loudness of a single tone can be approximated by Stevens's power law in which SPL has an exponent of 0.67. It is sometimes stated that loudness is a subjective measure, often confused with physical measures of sound strength such as sound pressure, sound pressure level (in decibels), sound intensity or sound power. It is the length in space of a sound. The period of a sound wave is the time taken for one wavelength to pass a certain point before a new wave begins. A longer wave period represents a lower pitch sound. The third part of a sound wave is the amplitude. The amplitude of a sound wave represents the loudness of the sound. Look at the following pairs and decide which item has greater amplitude: 1 yell or whisper. 2 siren or cat meow. 3 mosquito buzz or car alarm. 4 fireworks or violin. has to do with the differences among sounds that have the same pitch and loudness The ear can respond to a remarkable range of sound amplitude. (Amplitude corresponds to the quality known as loudness.) The ratio between the threshold of pain and the threshold of sensation is on the order of 130 dB, or ten trillion to one. The judgment of relative sounds is more or less logarithmic, such that a tenfold increase in sound power is described as twice as loud. When the air particles begin vibrating the air inside your ear, you hear a sound. This chain reaction continues until the particles run out of energy. This is what you call a "sound wave." Volume is the intensity of a sound wave. It is directly related to amplitude, which is the height of a sound wave. Query: how do we hear the loudness of a sound
A:
The loudness of a sound in measured in decibels.