The validation of acoustic environment simulator to determine the relationship between sound objects and soundscape

An acoustic environment simulator is a system that facilitates acoustic environment composition by controlling the parameters of sound objects (both background and sound events), allowing the user to compose and compare soundscapes against their expectations. By using the acoustic environment simulator, data regarding parameters of sound objects, such as their sound level and selection, can be obtained. Furthermore, these data can be used to understand the relationship between the sound objects and the soundscapes. This paper describes the development and validation of an acoustic environment simulator, which can be used to design a complex acoustic environment in the laboratory according to the expectations of the user. Validation of the simulated soundscape, whether the composed acoustic environment has the same soundscape dimension characteristics as previous in-situ and other laboratory experiments, was conducted by reproducing acoustic environment compositions using a two-dimensional ambisonic system in the laboratory. Listener responses on semantic differential scales were reduced to three reliable soundscape dimensions by principal component analysis: Calmness/Relaxation (40%), Dynamics/Vibrancy (12%), and Communication (11%). These three soundscape dimensions are consistent with a previous study conducted in situ. The results reported here indicate that acoustic environment composition can successfully imitate the soundscape dimensions of an actual acoustic environment

The effect of sound level on perception of reproduced soundscapes

The aim of this work was to investigate the perception of soundscape reproduced by an ambisonic reproduction system on a horizontal plane, how the experience of space affected the perception of soundscape reproduction, and how the sound level adjustment on soundscape reproduction affected the perception of soundscape compared with actual conditions. There were three experiments conducted: a soundwalk in situ in Manchester (United Kingdom) city centre, listening tests in Salford (United Kingdom), and listening tests in Bandung (Indonesia). The listening tests used material recorded from four locations on the soundwalk route in Manchester. The Salford listening tests were performed at the in-situ measured sound level, and the participants were asked to adjust the sound level to the level that represents actual locations. The listening test in Bandung was conducted to understand the effect of participants who never come to the actual location to the perception of soundscape and the sound level adjustment. The listening tests in Bandung were conducted at the in situ sound level, at 9.5 dB below the in situ sound level (based on the preference sound level from the experiment in Salford), and the participants were also requested to adjust the sound level to the level that represents the actual space (to examine the consistency with the experiment in Salford). In each case, soundscape perception was measured on 19 semantic differential scales. Analysis of the semantic differential results showed that the ambisonic reproduction produced a similar subjective experience to the in situ soundwalk when the reproduction sound level was 9.5 dB lower than the actual sound level in situ. Reproduction at the actual sound level in situ produced a different dimensional space. The study shows that the sound level adjustment of soundscape reproduction in laboratory experiment produces more ecologically valid results compared to the reproduction at the actual sound level in situ

Soundscape composition and relationship between sound objects and soundscape dimensions of an urban area

Previous studies of soundscape have tried to understand the relationship between sound objects and soundscape rating, resulting in the categorisation of general sound objects according to positive or negative perceptions. This study tries to determine the relationship and interaction between specific sound objects in a soundscape and the soundscape dimensions. This study is divided into four steps: testing the validity of soundscape study in the laboratory, the application of soundscape recording, the development of a soundscape environment simulator, and the determination of the relationship between specific sound objects and soundscape dimensions according to expectations and preferences regarding sound objects. The first step confirms three reliable soundscape dimensions from in situ and laboratory experiments (measured using the same semantic scales for both): Relaxation, Dynamics and Communication. It also confirms the validity of laboratory experiments compared with in situ ones. Furthermore, the effect of sound level adjustment on soundscape reproduction in the laboratory is investigated.The second step, using soundscape recording, confirms that the common method of analysing the relationship between sound objects and soundscape rating (in situ experiment and soundscape reproduction) is not adequate due to limitations in the selection of sound objects and control over their parameters. A different method is proposed to deal with these limitations: using a soundscape environment simulator. A soundscape environment simulator is therefore developed to understand the relationship and interaction between sound objects in a soundscape and the perception of the soundscape. The soundscape environment simulator can be used to compose complex soundscapes. Furthermore, semantic differential analysis confirms that soundscape composition can represent an actual soundscape. Finally, two experiments are conducted using the soundscape environment simulator to study expectations and preferences of sound objects in a soundscape. The study succeeds in explaining the relationship and interaction between specific sound objects and the rating of soundscape. Furthermore, a perception model regarding the preference of sound objects used in the soundscape environment simulator and the soundscape dimensions is developed and implemented in the soundscape environment simulator. This implementation allows the simulator to predict perceptions of the soundscapes composed by the simulator