## 1 Introduction
In Stage 2, soundscape planning and design scenarios are proposed based on the analysis of the existing soundscapes. The soundscape design proposals will then be simulated to be objectively and subjectively evaluated by stakeholders to determine the final soundscape design. In Stage 3, the final soundscape design will be implemented in situ. After implementation, validation of the soundscape design will be performed with iteration of Stage 1 for analysis of implemented soundscape design. Throughout the soundscape design process, soundscapes can be evaluated based on the real acoustic environment or virtual (reproduced or synthesized) environment [6; 11]. Similarly, in Stage 1 (analysis of existing soundscape) and Stage 3 (implementation of soundscape design), soundscapes  
Figure 1: Schematic illustration of soundscape design process, types of acoustic environment and required techniques. can be assessed in real or reproduced acoustic environments. The reproduced acoustic environment is constructed from audio recordings in the real world. If the physical location for soundscape implementation is not available (i.e., not built), future soundscape design scenarios might also be evaluated using synthesized (or simulated) acoustic environment in Stage 2 (soundscape planning and design). Moreover, augmented acoustic technologies consisting of synthesized and real sounds can also be applied in soundscape design stage if the physical locations are available. A real acoustic environment is evaluated in situ by means of field study methods, such as soundwalk and behavior observations, which generally focus on the short-term in situ experience [6; 11]. Narrative interview and social survey usually deals with long-term responses or recalled experiences based on the real acoustic environment [12; 13; 14]. In contrast, the virtual acoustic environment, created by recording followed by reproduction, are usually evaluated in a laboratory conditions [6; 11]. [PERSON] et al. [11] reviewed the advantages and limitations of such methods for soundscape assessment. Evaluation methods in the real acoustic environments are advantageous as they provide the most realistic representation of the real-life settings, which can guarantee high ecological validity. However, those methods are subjected to uncontrolled factors, such as temperature, humidity, daylight and wind speed. Accordingly, such methods may yield results that are difficult to generalized as they are limited to a specific context. These methods have been primarily applied to collect and characterize the existing acoustic environment at the early stages in urban soundscape planning and to validate the soundscape design at the implementation stages [6; 10; 15]. On the other hand, the virtual acoustic environment, are usually evaluated under controlled laboratory conditions. Researchers can design and control the experimental variables, such that it enables us to investigate various casual relationships or correlations. A laboratory-based experiment can obtain results that minimize the effects of other distracting environmental factors. Regardless of the strengths of the laboratory experiments based on virtual acoustic environment, criticisms on discrepancies between virtual and real environments, such as the absence of physical contact and possible perceptual alterations, have been raised. In general, the more control researchers exert in a laboratory experiment, the less ecological validity the findings have, which can be less generalized to real-life scenarios [11; 16]. Despite this limitation, acoustic simulation and reproduction techniques can provide powerful tools to evaluate the performance of different soundscape design approaches in Stage 2 before they are implemented in the real world [11]. Currently, the ISO WG54 is working on the Part 2 of the soundscape assessment standard to provide information on minimum reporting requirement for soundscape studies and applications [17].