Sonar.
That depends how close you measure to the fan. The closer - the louder! The distance is very important if you measure with a sound pressure level meter.
-- Measure the distance between two points.-- Measure the time it takes the jet to fly from one point to the other one.-- The speed of the jet between the two points is(the distance between them)/(the time it takes to fly from one to the other)
Wavelenght
Feelings of loudness are different from person to person. So don't talk of "measuring" the "loudness".For psycho acoustic values we have units to express loudness:Sone (loudness N) and Phon (loudness level L).You can really measure the sound pressure with a sound pressure level meter. That is measured in dB SPL. Loudness is a subjective measure but sound pressure is an objective measure. But that is different. Don't mix it up. Scroll down to related links and look for more on decreasing of sound pressure with distance.
That depends how close you measure to the mouth speaker. The closer - the louder! The distance is very important if you measure with a sound pressure level meter. A conversation in 1 meter distance may have 60 decibels.
to measure sound from distance use decibels
The process of using sound waves underwater to measure distance is called sonar, which stands for Sound Navigation and Ranging. Sonar systems emit sound waves that bounce off objects in the water and are then detected to determine the distance to the object.
Sound waves are used in underwater distance measurement through a process called sonar (Sound Navigation and Ranging). An initial sound pulse is sent, which bounces off an object underwater and returns to the source. By measuring the time it takes for the sound pulse to return, the distance to the object can be calculated based on the speed of sound in water.
An echo can be used to measure distance by sending out a sound pulse and measuring the time it takes for the sound to bounce off the object and return as an echo. The distance can be calculated using the time taken for the sound to travel back and forth and the speed of sound in the medium. By knowing the speed of sound and the time it takes for the sound to return, the distance to the object can be determined.
You measure sound in megahertz.
The measure of how strong a sound seems is called its amplitude or loudness. Amplitude refers to the height of the sound wave, which correlates with the sound's perceived volume.
Loudness is the perceived intensity of sound, measured in decibels (dB). Distance affects loudness by causing sound to decrease in intensity the further it travels, as sound waves disperse in all directions. The inverse square law states that the sound pressure level decreases by 6 dB for each doubling of distance from the sound source.
A sonar system measures distance by sending out sound waves that bounce off an object and return to the sensor. The system calculates the distance based on the time it takes for the sound waves to return. By knowing the speed of sound in water or air, the system can accurately determine the distance to the object.
The range of distance within which sound can be heard is called the audible range. This refers to the distance at which sound waves are able to reach a person's ear and be perceived as sound.
One way to investigate the speed of sound is to measure the time it takes for a sound wave to travel a known distance, like using a stopwatch to measure the time between the sight of a lightning bolt and the sound of thunder. Another method is to use a resonance tube or other equipment to create sound waves and measure the wavelengths at different frequencies to calculate the speed of sound.
The distance from crest to crest in a sound wave is called the wavelength. It represents the physical length of one cycle of the wave and is directly related to the frequency of the sound wave.
The term for the distance between two sound frequencies or pitches is called "interval."