dB(A) is defined as Decibels on the A-weighted Scale. Leg24 is defined as equivalent Continuous Sound Level, normalized for 24 hours. L10 Peak Hour is defined as equivalent Continuous Sound Level, normalized for 10 hours, while allowing an excess over the specified noise level for 10% of the hour.
The number represented by db(A) Leg24 is generally a good representation of annoyance. The descriptor dB(A) closely represents true human hearing and the descriptor Leg24 has been used for years and proven to be acceptable.