Is there science behind that? Snoezelen Rooms®

Elizabeth Hardesty, MA, BCBA, Breanna Roberts, MA, BCBA, and Thomas Zane, PhD, BCBA-D
Department of Applied Behavioral Science, University of Kansas

Is there science behind that In this article, we will discuss background information and current research on Snoezelen Rooms® or multi-sensory environments (MSE) that claim to treat symptoms of ASD including atypical sensory responses. Atypical sensory responses are now a key component to receiving an autism spectrum disorder (ASD) diagnosis, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association [APA], 2013). Furthermore, prior to being included as a diagnostic criterion, hyper- or hyporeactivity to sensory input or unusual interests in sensory aspects of the environment were commonly reported by individuals with ASD (e.g., Kanner, 1943; Kojovic et al., 2019). For example, a child with autism may spend more time rocking or jumping compared to their typically developing peers. Atypical responses to sensory input have been described as “sensory processing disorders” as a shorthand by professionals who commonly work with individuals with ASD (e.g., occupational therapists, speech language pathologists, pediatricians). It is argued by some that 80-90% of individuals with ASD are reported to have such sensory processing disorders (e.g., Schaaf & Miller, 2005). However, it is important to note that the American Academy of Pediatrics (AAP) and DSM-5 does not recognize “sensory processing disorders” as a standalone diagnosis and does not recommend related sensory-based therapies (AAP Council on Children with Disabilities, Section on Complementary and Integrative Medicine, 2012; APA, 2013). For more information on sensory processing, sensory integration, and ASD, we refer readers to the “Is There Science Behind That” article on sensory diets (Holehan & Zane, 2021).

What is a Snoezelen Room®?

The concept of “Snoezelen” comes from two Dutch words: “snuffelen” meaning to seek or explore and “doezelen” meaning to relax. Initially developed in the 1970s by two Dutch therapists, Jan Hulsegge and Ad Verheul, the first Snoezelen environment was trialed at an institution for individuals with developmental and intellectual disabilities. The goal of this first multi-sensory environment was “to increase enjoyment and sensory experience” for the individuals who resided at the institution (Snoezelen Multi-Sensory Environments, n.d.). Today, Snoezelen Rooms® claim to be beneficial in a variety of settings (e.g., schools, hospitals, community centers) and are purported to aid in learning, development, relaxation, and support of individuals with sensory processing and related disorders. Further, the Snoezelen website claims that “the limits using a multi-sensory environment are with the imagination of the facilitator and the possibilities are endless” (Snoezelen Multi-Sensory Environments, n.d.b). Snoezelen Rooms® partner with specific manufacturers in various countries to offer “high-quality” products to customers. However, no specific quality measures or definitions for “high-quality” are available on the Snoezelen Room® website. Additionally, Snoezelen MSEs® offer an online e-learning course to supplement marketed products by providing those who will work in the Snoezelen Room® with information on sensory input, sensory processing, and how to design a Snoezelen Room® session. Overall, Snoezelen Rooms® are marketed as suitable, adjustable, and safe environments in which various professionals can conduct therapy to achieve greater prosocial behavior and decrease challenging behavior by addressing the sensory needs of individuals.

How are Snoezelen Rooms® Implemented with Individuals with Autism?

As stated on the Snoezelen website: “Multi-Sensory Environments (MSEs) can provide a space where a variety of interventions can be tailored to meet a need (or needs) quickly and easily, whether it be therapeutic, educational, or focused on using sensory equipment to calm, soothe, or stimulate” (Snoezelen MSEs, n.d.). Proponents of Snoezelen Rooms® indicate that relaxation and mindfulness are the ultimate goals of the room; therefore, Snoezelen Rooms® should be set up in a manner to promote individuals to become and remain calm. For some individuals, Snoezelen Rooms® are locations where the sensory stimuli present in the space can be incorporated into various therapies. These sessions are typically led by professionals, such as speech language pathologists, physical therapists, or occupational therapists. For others, Snoezelen Rooms® are spaces with a variety of stimuli designed to engage various senses (e.g., touch, smell, sight) without any specific goal or purpose other than relaxation. In these cases, Snoezelen Room® sessions are unstructured and non-directed by therapists, teachers, or caregivers.

The Snoezelen Room® website states that these rooms are customized based on their ultimate purpose and may vary due to size, materials, and limitations of the space (e.g., building code compliance, financial limitations; Snoezelen MSEs, n.d.b). For example, some Snoezelen Rooms® are large with a variety of sensory items and activities such as fiber optic light ropes, swings, beanbag chairs, LED light wall panels, audio-visual experiences projected on walls (e.g., virtual nature walks), bubble tubes, or mirrors (Snoezelen MSEs, n.d.a). Other Snoezelen Rooms® may be partitioned off sections of a larger room and consist of a variety of more temporary items such as mirrors, pillows, rugs, and small fidget toys. Little guidance on creating and developing a Snoezelen Room® is available without requesting a consultation from a Snoezelen Room® representative. According to the Snoezelen Room® website, Snoezelen Rooms® typically consist of many Snoezelen products in a room designed specifically for the needs of the individual who will use it most. Snoezelen recommends service providers work with a Snoezelen representative to design and curate an individualized environment. This process typically includes providers purchasing various products included on the Snoezelen Room® website, such as bubble tubes, fiber optic lights, swings, music systems, switches, and sensory panels that change light color after pressure is applied.

Snoezelen Rooms®: Is There Science Behind That?

Before discussing the current research on Snoezelen Rooms®, we find it important to address the conceptualization of Snoezelen Rooms® in treating “sensory processing disorders” by allowing access to various sensory experiences. Sensory integration theory is alluded to by the Snoezelen Room® website (Snoezelen MSEs; n.d.) and cited in the introduction section of promoted research (Novakovic et al., 2019). Sensory integration theory was initially conceptualized by Dr. A. Jean Ayers in the 1970s as a framework to describe how the nervous system integrates sensory input into action (Ayers, 1972; 1979). As stated previously, “sensory processing disorders” are not formally recognized by either the DSM-5 (APA, 2013) or the AAP (2012). Furthermore, the AAP (2012) summarizes research on sensory integration therapies as “limited and inconclusive” (p. 1186). For more information on sensory integration theory, we refer readers to the Sensory Integration Theory and Ayres Sensory Integration® treatment summary (Gasiewski & Weiss, 2022).

Currently, research on Snoezelen Rooms® can be separated into two main categories. The first category consists of evaluating participant outcomes when comparing Snoezelen Room® access to no Snoezelen Room® access. The second category consists of evaluating methods to determine specific stimuli to include in a Snoezelen Room®. Most research on Snoezelen Rooms® falls into the first category, exploring the effects of Snoezelen Room® access compared to no access. The Snoezelen Room® website only provides one research study exploring the effects of Snoezelen Rooms® for individuals with ASD. Novakovic et al. (2019) sought to determine the effects of a multi-sensory environment on the severity of ASD and repetitive behaviors in adolescents and adults as scored on the Childhood Autism Rating Scale (CARS). Individuals in the treatment group received Snoezelen Room® sessions three times per week for three months, compared to a control group who did not receive Snoezelen Room® sessions nor any additional therapies. Snoezelen Room® sessions were reported to be 30 minutes in length and participants were exposed to the Snoezelen Room® in groups of three. Snoezelen Room® sessions were conducted by special educators who followed a “non-directive approach” in which the participants freely moved around the room and engaged with items and activities without instructions or prompting. Results indicated a statistically significant decrease in CARS scores for those in the treatment group compared to those in the control group. However, these results must be interpreted with caution. The researchers only evaluated outcomes using the standardized rating scale completed by caregivers rather than direct observation and measurement of behavior. Furthermore, the authors did not clarify whether caregivers knew which group each participant was assigned to. This raises a concern that caregivers, when completing the Childhood Autism Rating Scale (CARS) at the study’s conclusion, might have unintentionally skewed their answers to favor the use of Snoezelen Rooms®. Additionally, the study provided no information on how specific individuals were impacted, and no procedural fidelity measures were taken. This means there is no way to confirm if therapists accurately followed the ‘”non-directive” procedures.

More recently, De Domenico et al. (2024) compared the Second Edition Childhood Autism Rating Scale (CARS-2) scores of 20 children with ASD before and after exposure to either play therapy (control group) or structured Snoezelen Room® therapy (experimental group). Although the results of the study did not show a significant difference in CARS-2 scores between the groups, those exposed to the structured Snoezelen Room® therapy were observed to show an improvement in sensory behavior related to touch, taste, and smell. Unlike Novakovic et al. (2019), Snoezelen Room® sessions in De Domenico et al. (2024) were described as having clear outcomes for each sensory activity such as labeling and identifying smells, mutual gaze, and naming animals, shapes, colors, and objects. Specific goals were identified for each participant based on their “emerging skill repertoire” (De Domenico et al., 2024, p. 7). No other details about the intervention (e.g., number of trial exposures, type of data collected within sessions, or prompting hierarchy) were provided by the authors. Similar to Novakovic et al. (2019), De Domenico et al. (2024) only evaluated outcomes using the standardized rating scale completed by caregivers rather than direct observation or measurement of behavior. These studies provide little evidence to support positive outcomes for individuals with ASD from the use of Snoezelen Rooms®.

In a notable exception to these limitations, McKee et al. (2007) collected data on the occurrence of challenging and prosocial behavior throughout the day for three adult participants with ASD residing in an inpatient setting. Participants were exposed to 28 days without access to the Snoezelen Room® followed by 28 days with daily access to the Snoezelen Room®. Results indicated that two of three participants’ daily levels of challenging behavior and prosocial behaviors were not impacted by access to the Snoezelen Room®. Interestingly, for the third participant, levels of challenging behavior increased with prolonged access to the Snoezelen Room® while prosocial behaviors decreased. Results for all participants were replicated by removing and then reapplying the intervention. This second test confirmed the lack of change in behavior for the first two participants and demonstrated a cause-and-effect relationship between the the Snoezelen Room® and the detrimental behavior change for the third participant.

There is a lack of research falling into the second category regarding the best way to design an effective or preferred Snoezelen Room®. Specific, step-by-step guides for developing these rooms are unavailable, both on the Snoezelen Room® website and in existing research (Snoezelen MSEs, n.d.b). For example, a study by Fava and Strauss (2010) evaluated the behavior of adults with autism spectrum disorder (ASD) or other intellectual/developmental disabilities. They observed how participants’ challenging and prosocial behaviors changed when in three different environments: (a) the living room of their residential institution, (b) a general Snoezelen Room® containing various sensory activities and items, or (c) a room with sensory activities and items tailored to their individual preferences. Participants regularly used the living room, and no extra encouragement was given to interact with items or activities in any of the settings. During Snoezelen Room® sessions, all activities and items were available without prompting or encouragement from the caregiver conducting the session. In the final individually tailored room, participants had access only to items and activities previously identified as preferred by them in a preference assessment. Additionally, caregivers actively encouraged participants to use the items or activities in the room. If a participant was inactive with an item for two minutes, caregivers offered other preferred items or activities. The study’s results showed that participants with autism spectrum disorder (ASD) exhibited less challenging behavior and stereotypy only after exposure to the Snoezelen Room®. However, participants without ASD engaged in higher levels of prosocial behavior only when exposed to the preferred materials sessions.

Despite the clear decrease in challenging and stereotypic behavior following Snoezelen Room® exposure, the study has a few limitations worth noting. First, no participant had experience in each room. Therefore, it is unclear if the changes in behavior were a result of the different rooms or differences that already existed between the individual participants. Thus, it is unclear if the Snoezelen Room® would lead to impactful changes on an individual basis. Second, there were procedural differences between Snoezelen Room® and preferred materials sessions that may have influenced levels of challenging and prosocial behaviors both within and outside of the session. Decades of research on functional behavior assessment have shown that escape from instructions is the most common underlying reason for individuals to engage in challenging behavior (Beavers et al., 2013; Melanson & Fahmie, 2023). Given this information, it is unsurprising that encouraging participants to use preferred items (an instruction) during the preferred materials sessions may have resulted in higher levels of challenging behavior compared to the procedures used during Snoezelen Room® sessions (which included no instruction). Finally, the methods used to determine participants’ preferences in this study did not follow the best practices recommended at the time (Hagopian et al., 2004). The researchers stated they combined two common methods for identifying preferences, but they did not explain their exact procedures clearly enough for other researchers to repeat the study and confirm the results.

Similarly, Unwin et al. (2021) evaluated the extent to which participant control over the items in the Snoezelen Room® influenced behavior, cognition, and arousal levels of 41 child participants with ASD. During “active-change” sessions, the Snoezelen Room® stimuli changed when the participants interacted with them. For example, a light panel on the wall would change color only if the participant pressed on the screen. Alternatively, during “passive-change” sessions, the Snoezelen Room® stimuli changed on a time-based schedule, independent of the participant’s interaction with the stimuli. For example, a light panel on the wall would change color every minute. Notably, all participants were exposed to both conditions. Results indicated that having control of the Snoezelen Room® stimuli was correlated with reductions in repetitive motor behaviors, sensory behavior, activity, stereotypical speech, and an increase in attention. However, no significant changes in social behaviors, anxiety, positive affect, or biological arousal were observed.

What is the Gist?

Both in practice and research, it is unclear what a Snoezelen Room® “session” looks like aside from designing an aesthetically pleasing room with various sensory input items or activities. Procedural details are either not published or vary widely across research groups, as shown by procedural differences between Fava & Strauss (2010) and De Domenico et al. (2024). Therefore, more systematic evaluation on many aspects of Snoezelen Rooms®, such as how Snoezelen Rooms® are designed and what Snoezelen “sessions” consist of, is required before Snoezelen Rooms® can be evaluated to determine if they could be considered an evidence-based practice. Like the conclusions drawn four years ago on Sensory Diets by Holehan and Zane (2021), we found little evidence to support the use of Snoezelen Rooms® as a therapeutic intervention for individuals with ASD. It is important to note that Snoezelen Room® materials are exclusively sold by specific contractors in each country. Thus, cost is likely to be a barrier to many attempting to create full and uniquely designed Snoezelen Rooms®. We do not recommend procuring or designating resources to specifically design a Snoezelen Room® at this time. This decision is based on two key factors: a lack of clear evidence supporting the use of Snoezelen Rooms® for individuals with autism and a lack of transparency regarding the procedures employed within these rooms.

What Else Should We Consider?

Despite the lack of information and scientific evidence to support Snoezelen Rooms® as an overarching intervention theory, specific items or activities in Snoezelen Rooms® may be preferred by individuals with ASD or may be associated with reduction in negative states (i.e., are calming). Access to a variety of items may widen an individual’s interest in items and activities that can then be provided as (a) a reward following desired behavior (i.e., used as a reinforcer), (b) provided as a break on a time-based schedule, or (c) be used to teach individuals to practice and request relaxing activities. Access to preferred items and activities may promote a better quality of life, provide opportunities for engagement and social interaction, and effectively compete with challenging or stereotypic behavior when provided freely. In other words, having a variety of preferred and engaging items throughout a person’s day “for free” may increase desired or prosocial behavior and decrease challenging behavior. This suggestion is based on behavior-analytic research and practice recommendations related to preference assessments (for summary, see Hagopian et al., 2004; Karsten et al., 2011; Lill et al., 2021; Virues-Ortega et al., 2014), competing stimulus assessments (for review, see Haddock & Hagopian, 2020), and the prevention, assessment, and intervention of challenging behavior (see Ala’i-Rosales et al., 2019; Melanson & Fahmie, 2023). Furthermore, according to the US Surgeon General (1999), the National Standards Project (2015) at the National Autism Center, the National Professional Development Center (NPDC) on ASD at the Frank Porter Graham Child Development Institute at the University of North Carolina at Chapel Hill (2020), and the AAP (2020), behavior-analytic interventions have been and continue to remain an evidence-based intervention to decrease maladaptive symptoms of ASD and increase adaptive and prosocial behaviors.

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Reference for this Article

Hardesty, E., Roberts, B., & Zane, T. (2025). Snoezelen Rooms®: Is there science behind that? Science in Autism Treatment, 22(7).

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