Röstfysiologi

Röstfysiologi, or voice physiology, is the scientific study of how the human voice is produced and controlled. The primary anatomical structures involved are the larynx, the vocal folds (true vocal cords), and the surrounding musculature. Air from the lungs is regulated by the diaphragm and intercostal muscles and passes through the trachea into the larynx. When the vocal folds are brought together by the action of intrinsic laryngeal muscles – the thyroarytenoid, cricothyroid, posterior cricoarytenoid, lateral cricoarytenoid, among others – the airflow creates vibration. The frequency of vibration, modulated by tension, length, and mass of the folds, determines the fundamental pitch of the sound.

Phonation is influenced by both viscous and elastic properties of the vocal fold tissues, and by the subglottal pressure maintained by the lung. The vocal tract, comprising the pharynx, oral cavity, soft palate, and nasal cavity, shapes the resulting sound by resonating and filtering it into distinct speech sounds. Neurological control, through the recurrent laryngeal nerve and superior laryngeal nerve, coordinates motor function, while sensory feedback from mucosal receptors and auditory perception adjust and refine voice production.

Abnormalities in voice physiology can arise from structural lesions, neuropathic lesions, or functional disorders such as muscle tension dysphonia. Clinical assessment often includes laryngoscopic imaging, acoustic analysis, and aerodynamic measurements. Voice therapy and, when necessary, surgical intervention target specific physiological mechanisms to restore normal phonation. Research in röstfysiologi spans basic science to clinical practice, incorporating biomechanics, acoustics, and neurophysiology to understand how humans produce, vary, and maintain vocal output.