Table 3.

Polyvagal-informed interventions and mechanisms

Intervention	Mechanism	Function
Sonic Augmentation Technology (e.g., Sonocea’s Rest and Restore Protocol)	Rhythmic acoustic modulation mirrors endogenous autonomic rhythms and signals brainstem centers	Supports co-regulation, visceral homeostasis, and immobilization without fear
Safe and Sound Protocol (SSP)	Prosodic auditory stimulation activates middle ear muscles and VVC pathways	Enhances social engagement readiness and shifts neuroception toward safety
Breath- and Rhythm-Based Practices (e.g., slow-paced breathing, vocal toning)	Stimulates vagal afferents and supports parasympathetic dominance	Improves regulation, interoceptive awareness, and emotional balance
HRV Biofeedback & Coherence Training	Trains awareness of vagal tone via real-time feedback on RSA and heart rate	Increases vagal and self-regulatory capacity
Vagus Nerve Stimulation (VNS)	Auricular taVNS, Cervical tcVNS	Augments and supports parasympathetic autonomic flexibility tone
Somatic and Relational Therapies (e.g., touch, co-regulation, movement)	Provide bottom-up cues of safety through embodied presence and rhythm	Reinforces safety signaling, facilitates state transitions, and supports relational engagement