Light and sound hypersensitivity in autism spectrum disorder: a systematic review focusing on age and gender bias

Background: Autism spectrum disorder (ASD) is often characterized by hypersensitivity to sensory stimuli, with 70-90% of autistic individuals experiencing such difficulties. In environments without appropriate accommodation, these sensitivities can cause discomfort; however, current guidelines for regulating light and sound remain limited, and evidence from current research indicates a striking asymmetry across ages and genders. Objectives: This systematic review synthesized 29 studies (2015-2025) to (1): characterize distinct auditory and visual sensory hypersensitivity profiles in ASD compared to typically development (TD) controls (2); identify mechanisms of reduced habituation and impaired multisensory integration (3); quantify and critique methodological biases (age, gender, and context); and (4) map critical research gaps for inclusive environmental studies. Methods: PRISMA guidelines and registered protocol (PROSPERO: CRD420251042397). Three databases (PubMed, Web of Science, Scopus) resulted in 410 records; 29 met the strict PICO criteria, involving experimental/observational assessment of auditory or visual responses with ASD-TD comparisons. Quality assessment utilized a 16-item DISCERN instrument specifically adapted for neuroscience research. Data extraction encompassed demographic attributes (age, gender) and behavioral outcomes. Results: Most studies examined auditory stimuli, with few focusing on lighting effects. Sensory responses of autistic individuals were atypical, including reduced habituation to sounds, impaired sensory gating, and increased sensitivity to noises. A natural soundscape is more effective at regulating the body than clinical white noise. Visual research is limited, with no studies on photophobia or modern lighting. Audiovisual studies show delayed speech processing, slower adaptation to asynchrony, and reduced susceptibility to multisensory illusions, reflecting detail-focused perception. Males and children predominate in most studies, and females are underrepresented, particularly in adult studies, creating an age and gender gap. Conclusion: Addressing critical gaps and biases in autism sensory processing and therapeutic opportunities is essential. Studies should encompass gender-balanced perspectives, lifespan development, and visual hypersensitivity, incorporating ecological validity and translating findings into actionable environmental standards. Rather than perpetuating historical biases, it is crucial to prioritize the needs of underrepresented groups. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251042397, identifier CRD420251042397.