Assessing the impact of human vocalizations on perceived tranquillity in residential garden soundscapes: an evaluation using the tranquillity rating assessment tool (TRAPT)

The perception of human vocalizations within different soundscapes is complex, shaped by factors such as voice quality, volume, information content, and the surrounding environment. Despite limited research in this area, this study aimed to examine the influence of human voices on perceived tranquillity in a residential garden context. Thirty participants were recruited to assess tranquillity levels in response to various human sounds, including café conversations, children playing, zipline users, market noise, university crowds, and stadium ambient noise. Additionally, traffic noise at different intensities was included for comparison with mechanical sounds previously evaluated using the Tranquillity Rating Assessment Tool (TRAPT). The experiment was conducted in a controlled listening environment with minimal ambient noise. Participants, using headphones calibrated via a head and torso simulator (HATS), were presented with a contextual garden video while rating each sound. Each sound stimulus was played for 10 seconds, followed by a 10-second assessment period. Results revealed that the perceived tranquillity levels of human vocalizations could be predicted with reasonable accuracy using TRAPT, though notable deviations were observed. These findings hold significant implications for urban planning and noise management, particularly in residential areas where human activity is anticipated to impact residents’ sense of tranquillity. Keywords. People noise, tranquillity, soundscape