equivalent sound level

Equivalent sound level, often abbreviated as Leq, is a measure used in acoustics to express an average sound pressure level over a specific period. It's a logarithmic average, meaning louder events have a greater influence on the overall value than a simple arithmetic average would suggest. This metric is particularly useful for describing community noise exposure, such as from aircraft, and is often used in conjunction with a day-night sound level (Ldn) that penalizes nighttime noise due to increased human sensitivity. Sound intensity itself, a measure of energy flow per unit area, is objectively measured in decibels (dB) using devices like sound-level meters. The human ear's perception of loudness is subjective and varies with frequency, which is why sound-level meters often incorporate frequency-weighting scales, like the A-weighting (dBA), to better reflect how humans perceive sound.123