My sources tell me that it is in fact legal.
Yes the loudness of a sound is called its intensity.
Sound intensity or acoustic intensity can be calculated from the objective measurement of the sound pressure. The loudness is a psycho-acoustic subjective feeling, which is difficult to measure.
Sound intensity is a physical quantity that measures the amount of sound energy passing through a unit area, expressed in watts per square meter. Loudness, on the other hand, is a perceptual response to sound intensity and is subjective. In general, as sound intensity increases, the perceived loudness also increases. However, the relationship between intensity and loudness is not linear but follows a logarithmic scale.
Loudness is really a subjective measure and is often confused with objective measures in decibel units of sound pressure or sound intensity.
Loudness is related to the amplitude of a sound wave. The higher the amplitude of a sound wave, the louder the sound will be perceived by our ears. Amplitude represents the intensity or strength of the sound wave.
If the amplitude of a sound wave increases, the loudness or volume of the sound also increases. This is because amplitude is directly related to the intensity of the sound wave, which our ears perceive as loudness.
Sound intensity or acoustic intensity can be calculated from the objective measurement of the sound pressure. The loudness is a psycho-acoustic subjective feeling, which is difficult to measure.
By its amplitude. Really loudness is sound intensity & intensity depends on square of amplitude ie. higher the amplitude higher the intensity which means higher the loudness.
Loudness is the quality of a sound that is the primary psychological correlate of physical strength or amplitude. Loudness is a subjective felt impression and is in some way related to the objective measure of sound pressure.
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 loudness of sound is determined by the amplitude or intensity of the sound wave. Greater amplitude or intensity results in a louder sound. The unit used to measure loudness is decibels (dB).
Loudness is to brightness as sound is to light.