sound barrier

sound-barrier的词性：
n.（名词）

1. See sonic barrier
参见 sonic barrier

2. A set of tall wooden, plastic, or concrete barriers placed along a road or highway to muffle the sound of traffic.
音障：一组高大的木制、塑断或混凝土屏障，放置于道路或高速公路两旁，消弱交通所发出的噪声