ONE VIEW:
Perceived loudness of sound is measured in Decibels (dB), which is a logarithmic scale. This means that the actual energy of sound that is 10 dB versus 20 dB is actually 10-fold more energetic, although the perception of sound (and light) closely resembles a human's perception. For example, leaves rustling would be about 10 dB, an everyday conversation around 65 dB, and a military jet far away 140 dB. The threshold of pain for a human is approximately 120 dB.
This relates to intensity (Power/Area) in the equation:
B = (10 dB)*log (I/Io)
Where B is the Decibel level, Io= 1012 W/m2 (Threshold of hearing), and I is the intensity.
The Decibel is used instead of intensity because of the nature of our hearing. Since we have such a large range of hearing, the intensities from the first paragraph would range from 10-11 to 102 .
The Bel is the actual base unit for sound intensity (named after Alexander Graham Bell), but the Bel is so large, it became convenient to use the Decibel, which is one tenth a Bel.
ANOTHER VIEW:
Perceived loudness is measured in sones. This is based on tests where people were asked to compare sounds and assess their relative "loudnesses". (The Bel is a measured value, rather than a perceived value.)
Reference sound intensity Io = 10^−12 W/m² (Threshold of human hearing). Reference sound intensity level LIo = 0 dB-SIL (Threshold of human hearing intensity level). The sound intensity I is measured in watts per meter squared. The sound intensity LI level is measured in decibels (dB).
You take a measuring microphone with a sound pressure level meter.
Loudness is determined by the amplitude of the sound waves.
The unit of sound intensity I is watts per meter squared (W/m²). Sound intensity is a sound energy quantity. Sound pressure deviations are moving our eardrums. The unit of sound pressure p is pascals (Pa) or newton per meter squared (N/m²). Sound pressure is a sound field quantity. Another answer: The most common unit of sound intensity is the decibel (dB). Reply: No! We got the sound intensity measured in W/m² and the sound intensity level we measure in decibels (dB). The question was "sound intensity".
Sound intensity is measured in watts per square meters, but our eardrums are only moved by the sound pressure measured in newtons per square meters or pascals.
The intensity of sound is dependent on the amplitude of the sound wave. The higher the amplitude, the greater the intensity of the sound. It is measured in decibels (dB) and corresponds to the loudness of the sound.
Sound intensity I is measured in watts per meter squared (W/m²). Look at the link: "Conversion of sound units (levels)".
The intensity of a sound wave is called sound intensity. It measures the amount of energy transmitted by the sound wave per unit area. Sound intensity is measured in decibels (dB).
Reference sound intensity Io = 10^−12 W/m² (Threshold of human hearing). Reference sound intensity level LIo = 0 dB-SIL (Threshold of human hearing intensity level). The sound intensity I is measured in watts per meter squared. The sound intensity LI level is measured in decibels (dB).
You take a measuring microphone with a sound pressure level meter.
Intensity is the perceived loudness of a sound, which is related to the amplitude of the sound wave. The greater the amplitude, the higher the intensity, resulting in a louder sound. Intensity is typically measured in decibels (dB).
The intensity of sound primarily depends on the amplitude of the sound wave. A higher amplitude corresponds to a louder sound. Sound intensity is measured in decibels (dB) and is perceived by our ears as volume.
Loudness of sound is measured in decibels (dB) which quantifies the intensity or volume of a sound. Softness of sound is generally perceived subjectively and does not have a standardized unit of measurement, but is often described as quiet or faint.
A sound level meter measures the intensity of sound in decibels. It consists of a microphone to capture the sound and a display to show the measured levels.
Two properties of sound are frequency, which determines the pitch of a sound, and amplitude, which determines the loudness or intensity of a sound. Frequency is measured in hertz (Hz) and amplitude is measured in decibels (dB).
Sound is normally measured is naturally measured in decibels (dB) which is a logarithmic scale.
The intensity of a sound is measured in decibels (dB), with higher decibel levels indicating louder sounds. The intensity is a measure of the energy that a sound wave carries, and can impact how loud a sound appears to our ears.