This systematic review had four main objectives: first, to characterise distinct auditory and visual sensory hypersensitivity profiles in autism compared to typically developing controls; second, to identify mechanisms like reduced habituation and impaired multisensory integration; third, to quantify and critique methodological biases related to age, gender, and context; and fourth, to map critical research gaps for inclusive environmental studies. For those who have been listening to the podcast from the start, you will remember that a systematic review is a structured literature review that follows the PRISMA criteria.

The review focused specifically on experimental and observational studies that directly assessed sensory responses to auditory or visual stimuli, rather than relying solely on caregiver reports or questionnaires. This approach allowed the researchers to examine what’s actually known from controlled studies versus what we might assume from interview-based research.

Methods

The researchers followed PRISMA guidelines and registered their protocol in PROSPERO. The search was restricted to peer-reviewed articles published between 2015 and 2025. After removing duplicates and applying eligibility criteria, 29 studies met all requirements for inclusion. Data extraction encompassed demographic attributes including age and gender, type of sensory stimulation employed, functional sensory variables like habituation and sensory gating, well-being variables, and main conclusions from each study.

The Results

Of the 29 studies, 16 focused exclusively on auditory stimulation, only two examined visual stimulation alone, and 11 investigated audiovisual paradigms. Participants’ ages ranged from 2 to 75 years, though age distribution wasn’t even across the range.

Auditory Hypersensitivity Findings

The review concluded that auditory processing in ASD differed from typical populations. This focus was on hypersensitivity and the review found that autistic individuals showed reduced habituation and adaptation compared to typically developing peers, scans showed prolonged neuronal activity in response to repetitive stimuli.

There were sensory gating deficits which led to impairments in the filtering of irrelevant sounds and increased responsiveness to distracting auditory stimuli.

A finding that was particularly interesting to me was that physiological responses were highly dependent on the sound. Task-irrelevant noise generally had negative impacts, but natural sounds like rainfall were often perceived as calming. Nature sounds were also more effective at suppressing physiological arousal than white noise, this has implications for the types of background noise we might recommended to the autistic individuals we work with.

Visual Hypersensitivity Findings

Research into the visual sense was limited, with no studies examining photophobia an abnormal sensitivity or intolerance to light, or modern lighting technologies like LEDs. The studies that did examine visual processing found physiological evidence of pupillary autonomic dysfunction, where altered pupillary light reflexes indicate a biological mechanism underlying photophobia. Autistic individuals also demonstrated strong detail-oriented bias in visual processing, prioritising specific elements over the global bigger picture. This is likely something that we have all probably observed in practice.

Audiovisual Integration

Studies examining audiovisual integration revealed slower adaptation to audiovisual asynchrony in autistic individuals. They encountered significant challenges merging auditory and visual inputs, this was attributed to a wider temporal integration window that disrupts the synchronisation necessary for cohesive multisensory perception.

Age Bias

The age bias was substantial. Whilst participants ranged from 2 to 75 years, the average age was 18 years with most studies focusing on childhood and adolescence. Very few studies examined middle-aged or older adults. Therefore, we know relatively little about how sensory hypersensitivity manifests, evolves, or impacts quality of life in adulthood and older age.

Gender Bias

Gender representation was also imbalanced. Women comprised only 21.79% of autistic participants on average, compared to 31.42% in typically developing control groups. Some studies had female participation rates as low as 5.9%. This severely limits the generalisability of findings to autistic women, who may have distinct sensory profiles, coping strategies and different hormonal influences on sensory processing to their male counterparts. I think this is probably reflective of the under diagnosis of women historically, as although the articles were published from 2015, the research will have been conduct prior to this as it can take a number of years to have work published after data collection.

Context Bias

Finally, most studies were conducted in highly controlled laboratory settings using simplified stimuli such as pure tones, brief flashes of light, clinical white noise. Only one study examined naturalistic auditory stimuli and no studies evaluated modern LED lighting, photophobia, or flicker frequencies, despite these being common in real-world environments. This creates what the researchers called an “ecological gap” between laboratory findings and the sensory reality autistic people navigate daily in the real world.

Practical Takeaways

First, it presents and summarises clear evidence that autistic individuals do experience auditory and visual sensations differently to their typically developing peers. The article explores some of the neurological reasons underpinning this if you are interested. It also indicates that sensory hypersensitivity isn’t limited to childhood, it persists across the lifespan and is not something that children will ‘grow out of’. Whilst some adaptation may occur, sensory sensitivities remain a lifelong feature requiring ongoing accommodation.

The review recognises that detail-focused perception isn’t simply a deficit—it represents a different perceptual style. Autistic students may process sensory information by attending to specific elements rather than global patterns. This will affect how they experience their environment. Additionally, the review provides neurological evidence that habituation is reduced, meaning that repeated stimuli don’t fade into the background as they might for neurotypical individuals. That humming light, ticking clock, or background chatter may remain equally noticeable throughout the day rather than becoming something the brain filters out. This has significant implications for classroom design and the importance of low arousal sensory breaks.

My biggest takeaway was probably the finding that natural sounds may be more regulating than white noise. This is something that I know I can suggest to families and schools which should be pretty simple to implement.

This study by Celestin and colleagues presents Sensory Maps 2.0, an enhanced approach to visualising and understanding the sensory properties of health care settings. They mapped sound, brightness and crowding density across different areas in the hospital to identify where the most sensory overload may occur. For example, noise levels were higher near entry points and brightness peaked in central naturally lit areas. I think this is a novel piece of research, and although it is unlikely that we can change some of the environmental sensations, it could be used to show individuals with sensory differences the areas in these spaces they may like to avoid or spend minimal amounts of time in.

This study by Zaguri-Vittenberg and colleagues examined social functioning in 77 preschool children, 38 with and 39 without sensory modulation difficulties. The research compared parent report of social skills and social participation between these groups, finding that children with sensory modulation difficulties demonstrated reduced social functioning compared to typically developing peers. Understanding these associations helps therapists recognise the broader impact of sensory modulation challenges on children’s social development and participation.

This scoping review by Takashima and colleagues examined procedural support strategies for neurodivergent children during medical procedures. The review synthesised evidence from 144 articles on effective approaches for supporting autistic children and others with neurodevelopmental differences through medical examinations and interventions. The most frequently used support strategies were visit preparation and support (n = 61, 42.4%), pharmacological agents (n = 48, 33.3%), and patient care plans/pathways (n = 43, 29.9%). The authors identified that there are significant gaps in procedural support strategies for neurodivergent children, particularly for conditions beyond autism. This is an area where OTs would be well placed to help with.