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By Paul North, Psychologist and Lead Author of Polyvagal Parenting Reviewed by Unyte Clinical Team |
Why do some children show remarkable progress following interventions such as the Safe and Sound Protocol (SSP), while others struggle to sustain therapeutic gains despite careful implementation?
While SSP is specifically designed to support nervous system regulation in children, adolescents and adults, an important question remains largely unexplored: when SSP is used therapeutically with children, how much does the surrounding environment — and, more specifically, the nervous systems of caregivers — influence outcomes? In simple terms, can a child truly benefit from SSP if the home environment remains chronically stressed and dysregulated?
To help children feel safe, we may first need to help parents feel safe.
Having been an SSP provider since its initial release in March 2017, I have repeatedly observed that the environment surrounding the child is often crucial to successful outcomes. If a child’s home environment remains characterized by chronic stress, unpredictability, or emotional dysregulation, the nervous system may continue to organize around protection, making greater calm, connection, and social engagement more difficult to access and sustain.
The SSP is grounded in Dr. Stephen Porges’ Polyvagal Theory. Emerging research suggests that SSP’s filtered acoustic stimulation may improve auditory processing of human speech frequencies, reduce auditory hypersensitivities, and support physiological states associated with increased autonomic regulation and social engagement (Kawai et al., 2023; Porges, 2022; Vincent et al., 2025). Clinical observations and published research show the intervention can improve emotional regulation, behavior, social engagement, and developmental progress, sometimes with remarkable therapeutic gains.
Even when providers carefully follow the principles taught in the Foundational SSP Training, children’s responses can vary. Some may show rapid improvement, while others require more time or repeated intervention, or experience only modest gains. What might help explain these different trajectories? One potentially important — and sometimes overlooked — influence is the caregiving environment.
One family, representative of several I have worked with over the years, illustrates this well. An autistic seven-year-old girl presented with a history of early, recurrent ear infections and marked auditory hypersensitivities, making her an excellent candidate for the SSP. Following her initial delivery of the SSP Core program, she made meaningful gains, but they were less pronounced than I had anticipated.
As I came to know the family, it became apparent that her father, despite being devoted and caring, struggled with emotional reactivity at home following years of military service and exposure to artillery. Although relatively controlled and composed in public, he found regulating his emotions within the family far more difficult. Rather than focusing solely on the child, we also began supporting the father’s nervous system through breathing practices, meditation, compassion-based exercises and, eventually, the SSP.
Over the following two months, his capacity for self-regulation increased noticeably, and with it the emotional climate of the home began to change. When the young girl completed a second round of SSP, the difference was striking. She became more socially engaged, her attentional focus improved, and she was better able to tolerate disappointment without becoming overwhelmed. While no single case can establish cause and effect, it reinforced what I have observed repeatedly throughout my clinical work: when the caregiving environment becomes physiologically safer, children often appear better able to benefit from therapeutic intervention.
One of Polyvagal Theory’s greatest contributions to modern trauma therapy has been providing clinicians with an organizing lens through which behavior can be understood not as pathology, but as adaptive responses developed in the service of survival. This same principle applies within the family system itself.
Children’s nervous systems are continuously, subconsciously scanning their environment for cues of safety and cues of danger. If caregivers themselves remain chronically stressed, emotionally unavailable, reactive, or inconsistent, how can the child’s nervous system truly relinquish the vigilance it detects is necessary for survival?
Rather than asking whether parents are regulated enough for a child to begin SSP, perhaps a more useful question is how we can support caregivers in becoming part of the therapeutic process itself. Even small increases in a caregiver’s capacity for self-regulation may strengthen co-regulation, improve the child’s sense of safety, and help consolidate the gains made during intervention.
Furthermore, when children first engage with interventions such as SSP that facilitate greater physiological safety, we sometimes observe an initial increase in activation. A Polyvagal-informed lens suggests this may reflect defensive survival states beginning to soften, prompting either vulnerability or previously suppressed emotional and physiological responses to emerge.
When caregivers have not yet been adequately prepared or supported to respond to this increased activation, therapeutic gains may be more difficult to consolidate. In essence, a child may complete an intervention designed to increase physiological safety, only to return each day to an environment that unconsciously reinforces vigilance.
Readiness need not be understood as a pass-or-fail test or a reason to withhold SSP. It may instead mean assessing caregiver stress and capacity alongside the child’s, preparing caregivers for possible changes in activation, agreeing on pacing and monitoring, and offering simple regulation practices or additional support. Where family stress is particularly high, caregiver-focused work may occur before or alongside the child’s SSP intervention.
What I have found repeatedly across almost four decades of clinical work is this: when parents feel safer, a ripple effect often occurs. Partners become more engaged. Children become less reactive. Relationships frequently strengthen, and intergenerational patterns of suffering begin to soften. I believe the future of effective nervous system interventions may depend not only on what we do for children, but on how deeply we support the nervous systems of the adults who care for them.
For clinicians, this may mean viewing caregiver regulation as part of the therapeutic process, not merely its context.
These ideas are explored further in Polyvagal Parenting, co-authored by Paul North, Dr. Lydia So and Michael Allison, with a foreword by Dr. Stephen W. Porges. Learn more about the upcoming release, and discover more titles and resources from Paul North →
References
Kawai, H., Kishimoto, M., Okahisa, Y., Sakamoto, S., Terada, S., & Takaki, M. (2023). Initial outcomes of the Safe and Sound Protocol on patients with adult autism spectrum disorder: Exploratory pilot study. International Journal of Environmental Research and Public Health, 20(6), 4862. https://doi.org/10.3390/ijerph20064862
Porges, S. W. (2022). Polyvagal theory: A science of safety. Frontiers in Integrative Neuroscience, 16, Article 871227. https://doi.org/10.3389/fnint.2022.871227
Vincent, V., Skaczkowski, G., Hughes-Barton, D., & Gunn, K. M. (2025). Effectiveness of sound-based interventions for improving functional outcomes in children: A systematic review of the evidence. Occupational Therapy International, 2025, Article 1693722. https://doi.org/10.1155/oti/1693722
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