Äänenvoimakkuus

Äänenvoimakkuus, often translated as loudness or volume, is the subjective perception of sound pressure. It is not a direct physical measurement but rather a psychological attribute related to the intensity of sound waves. While sound pressure level is a physical quantity measured in decibels (dB), loudness is a subjective experience that can vary between individuals and even for the same individual under different circumstances.

Several factors influence perceived loudness. The most significant is the sound pressure level; higher pressure generally results in a louder sound. However, the human ear's sensitivity to different frequencies is not uniform. We are most sensitive to frequencies in the range of 1 to 5 kHz, meaning sounds at these frequencies will be perceived as louder than sounds of the same pressure level at lower or higher frequencies. Duration also plays a role; longer-lasting sounds tend to be perceived as louder than very brief ones, even if their peak pressure levels are identical.

Loudness is often quantified using psychoacoustic scales such as the sone or phon. The sone scale aims to represent perceived loudness linearly, where doubling the sone value corresponds to a perceived doubling of loudness. The phon scale, on the other hand, is based on equal-loudness contours, which illustrate the sound pressure levels that are perceived as equally loud across different frequencies. Understanding the distinction between sound pressure and perceived loudness is crucial in fields like acoustics, audio engineering, and audiology, where managing sound levels and their impact on human perception is important.