Soundscape quality in suburban green areas and city parks

According to guidelines proposed in Sweden, at least 80% of the visitors in quiet areas should perceive the sound environment as good. This was the starting point for a questionnaire study on "soundscape quality" in four suburban green areas and in four city parks. The soundscapes in the suburban areas were completely dominated by sounds from nature (e.g., bird song and sounds from water), whereas traffic noise was a main component of the city-park soundscapes. Measured equivalent sound levels (from all sources) ranged from 42 to 50 dBA in the suburban green areas, and from 49 to 60dBA in the city parks (L-Aeq,(15min)). "Soundscape quality" was assessed by a five-point bipolar category scale. Among the respondents, 84-100% in the suburban green areas and 53-65% in the city parks assessed the soundscape as "Good" or "Very good". Thus, all suburban green areas but none of the city parks reached the stipulated goal (at least 80%). The soundcape quality was confirmed by attribute profiling using a set of 12 adjectives. Based on the visitor's responses, it is concluded that good soundscape quality can only be achieved if the traffic noise exposure in suburban green areas and city parks during day time is below 50 dBA.