Prediction of Noise Reduction Effect of Sound Barriers and Evaluation of Noise Annoyance

This study was conducted to assess noise annoyance following the installation of various types of sound barriers on elevated roads and to forecast the noise reduction effect. The level of annoyance was evaluated using a five-level linguistic rating scale, and noise values were anticipated for each floor of the building using Cadna/A software based on different road service levels. The results showed that for each service level road, the sound barrier’s noise reduction impact was most pronounced at heights of 3.5–5Formula: see textm, and the ratio of the acoustic barrier’s length extension to its distance from the building should not be greater than 4:1. After comparison, it was found that the fully enclosed sound barrier has the best noise reduction effect. Additionally, the noise annoyance level varied significantly at different service levels, with 60.5Formula: see textdB chosen as the noise threshold value. This study could offer an optional path for noise reduction facility design.