3.16 one-hour-average sound level. Time-averaged frequency-weighted sound level during a time period of one hour. Unit, decibel (dB); abbreviation, 1 HL; symbol, L1h.
3.16 one-hour-average sound level. Time-averaged frequency-weighted sound level during a time period of one hour. Unit, decibel (dB); abbreviation, 1 HL; symbol, L1h.