This note is a deep dive into H1 of the 4 research hypotheses.
What I Noticed
Through comprehensive review of prior research, one clear gap emerged.
Urban environment research using wearable devices (GPS×heart rate×accelerometer) and research on sensory hypersensitivity/misophonia do not intersect at all. (Based on PubMed, Google Scholar, and CiNii searches as of February 2026)
Research dealing with urban sound environments is biased toward fixed-point observation (stationary microphones) or laboratory experiments (sound presentation in soundproof rooms). Even for general citizens, few studies have measured "how much stress people experience in real-time while walking." For people with sensory hypersensitivity, there are globally zero such studies.
Why This Gap Exists
Three fields are unaware of each other.
- Wearable urban researchers (information engineering, urban planning) are unaware of the concepts of sensory hypersensitivity and misophonia. Their research targets "average responses of general citizens," with a tendency to exclude outliers.
- Sensory hypersensitivity researchers (psychology, auditory science) conduct research within laboratory experimental paradigms. Japanese research by Sakuma, Matsui and others also centers on questionnaire surveys and indoor acoustic measurements.
- Urban noise policy officials only look at time-averaged dB values. Individual sensory characteristics don't enter the judgment that "this road is below standard values, so there's no problem."
The research value of the Quiet Town Project lies at the intersection of these three domains.
The Closest Prior Research — And Why It's Insufficient
Before claiming it's completely zero, let's confirm the closest research.
Kanjo et al.'s (2017) NotiMind research tracked urban pedestrians' emotional states in real-time by combining smartphone sensors and wearable devices. The approach of integrating GPS location information, acceleration, ambient sound levels, and heart rate variability provides direct insights for this project's technical design. However, the subjects were general citizens, and no stratified analysis by sensory characteristics was performed.
Albacha et al. (2022) investigated daily sensory experiences in adults with autism spectrum using EMA (Ecological Momentary Assessment). While this represents important progress in recording daily stress "on-site" for people with sensory hypersensitivity, it centered on indoor environments and didn't include physiological data acquisition during outdoor movement.
In other words, research on "urban outdoor×during movement×physiological data" and research on "sensory hypersensitivity×daily life×EMA" each exist separately. No research combining these two approaches exists.
Hypothesis
People with sensory hypersensitivity and misophonia tendencies show significantly higher physiological stress responses (heart rate variability, galvanic skin response) compared to general citizens during urban outdoor movement, which constrains their frequency of going out and route selection.
Validation Approach
Participant Design: Two-group comparison between 15-20 adults with sensory hypersensitivity (self-identifying with ASD/misophonia) and 15-20 neurotypical adults matched for age and gender. Sample size calculated as minimum value assuming Cohen's d=0.8 (large effect size), α=0.05, 80% power. Degree of sensory hypersensitivity quantified using Glasgow Sensory Questionnaire (GSQ) and Amsterdam Misophonia Scale (A-MISO-S), also used as continuous variables in analysis.
Measurement Protocol:
- Walking the same route (approximately 2km route in Bunkyo Ward including main roads, residential areas, and parks)
- Continuous recording of heart rate variability (HRV) and electrodermal activity (EDA) with wearable sensors
- Simultaneous noise level recording with calibrated smartphone-mounted microphone
- Subjective stress recorded via smartphone EMA on 5-point scale (separating misophonia reactions, light stress, vibration stress)
- Cross-analysis by time period (morning rush, noon, evening, night) × route
- 8 sessions total per participant: 4 time periods × 2 repetitions each
Ethical Considerations: Since targeting people with sensory hypersensitivity, the research itself could become a stress source. Design allows interruption at any time, post-research debriefing, and referral to specialists as needed. Ethics review committee application planned for University of Tokyo or University of Tsukuba.
Insights from Hong Kong GEMA Research
Hong Kong's 2020 research (Geographic Ecological Momentary Assessment) investigated urban noise discomfort using GPS tracking + real-time subjective evaluation. While methodologically similar, subjects were general citizens only, with no analysis of people with sensory hypersensitivity. Applying this research to people with sensory hypersensitivity forms the core of the Quiet Town Project's Phase 1.
What This Research Can Demonstrate
If the hypothesis is supported, evidence would support the claim that "people with sensory hypersensitivity are canaries that first detect urban design flaws." Personal subjective suffering would be converted into the objective language of physiological data. Policymakers could redefine noise not as a "nuisance problem" but as a "health problem."
WHO's (2018) Environmental Noise Guidelines demonstrate causal relationships between noise exposure and cardiovascular disease, sleep disorders, and cognitive developmental disorders. However, this evidence targets general citizens, and the threshold at which people with sensory hypersensitivity experience health effects remains unknown. This research would be the first attempt to demonstrate that threshold with actual measurement data.
Another significance is extending the concept of "universal design" to sound environments. "Acoustic universal design" equivalent to tactile paving blocks for the visually impaired or slopes for wheelchair users has not yet been systematized. Data from people with sensory hypersensitivity would serve as foundational material for deriving those design standards.
References
Environmental Noise Guidelines for the European Region
World Health Organization (WHO). WHO Regional Office for Europe
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NotiMind: Utilizing Responses to Smart Phone Notifications as Affective Sensors
Kanjo, E., Kuss, D. J., & Ang, C. S.. IEEE Access, 5, 22023-22035
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Everyday sensory experiences of autistic adults: An ecological momentary assessment study
Albacha, A. et al.. Autism
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Geographic Ecological Momentary Assessment of noise annoyance in Hong Kong
Lam, K. C. & Chan, P. K.. International Journal of Health Geographics, 19, 45
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聴覚過敏と暮らしの音環境
佐久間哲哉. 日本音響学会誌, 77(5), 296-301
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