Subjective response to audio-visual environments - Combinations of low frequency noise, natural sounds and urban environments

Abstract

In today's urban environment, ventilation and low frequency noise from ventilation systems inside urban patios have become just about unavoidable. This study investigates if the perception of low frequency ventilation noise can be made more positive. To do this, a binaural recording of ventilation noise was done and pictures of two simular urban patios but with different degree of vegetation were taken. Recordings of birdsong and whispering leaves were also gathered. Ventilation noise alone or with addition of birdsong or whispering leaves was used as acoustic stimuli. A group of 30 Swedish test persons were exposed to six audio-visual environments created by combinations of the two pictures and the three sounds. After the exposures the participants filled ot questionnaires that were designed to give subjective ratings of the environments. The response to the audio-visual environments and interrelationships between audio and visual stimuli were analyzed. The results showed that the perception of an environment containing a low frequency noise could be improved with either visual stimuli or natural sounds. By adding natural sounds the environment was experienced as significantly more positive than without natural sounds. The environment was also perceived as significantly more positive when vegetation was present in the visual stimuli.