Table 2.

Comparative summary of wind instrument training, mindful/slow breathing and white-noise interventions

Intervention	Mechanism of action (keywords)	Evidence level	Target population	Adherence (typical)
Wind instrument training[9,11,43,44]	Active breath control; self-generated auditory biofeedback; upper-airway conditioning; possible ∼0.1 Hz pacing	RCT in OSA; small interventional/feasibility studies	Snoring/mild-moderate OSA; anxiety/sleep complaints; pulmonary rehab adjunct	Moderate-high with lessons + home logs; learning curve; low equipment burden
Mindful/slow breathing [7,45,46,47]	Slow paced breathing (∼0.08–0.12 Hz); vagal up-regulation; HRV resonance; attentional focus	Multiple RCTs; meta-analyses on HRV and symptoms; insomnia crossover data	Anxiety/insomnia; general population; low-resource settings	Variable; improves with app/biofeedback prompts; simple to deploy
White noise/continuous sound[48,49,50]	Broadband masking; acoustic predictability; arousal stabilisation	Systematic reviews; mixed trial results; setting-dependent	Noise-sensitive sleepers; urban/noisy environments; sleep-onset latency	High short-term; long-term variable; device/partner tolerance matters

Abbreviations: HRV, heart-rate variability; OSA, obstructive sleep apnoea; RCT, randomised controlled trial.