The barrier has resulted in a dramatic drop in subjective noise annoyance for homes directly along the freeway. On a seven-point scale the ratings of annoyance drop from 5 (extremely objectionable) to around 3 (moderately objectionable). This is equivalent to moving these homes back one block. There is also a very striking drop in subjective annoyance for homes behind the first row. The ratings drop from 4 (very objectionable) to somewhat below 3 (moderately objectionable).
