Acoustic analysis of swallowing sounds: a new technique for assessing dysphagia

• Published in: Journal of rehabilitation medicine Vol. 41; no. 8; pp. 639 - 645
• Main Authors: Santamato, Andrea, Panza, Francesco, Solfrizzi, Vincenzo, Russo, Anna, Frisardi, Vincenza, Megna, Marisa, Ranieri, Maurizio, Fiore, Pietro
• Format: Journal Article
• Language: English
• Published: Sweden 01.07.2009
• Subjects: Acoustics; Adult; Aged; Apnoea; Aspiration; Auscultation - methods; Confidence intervals; Deglutition - physiology; Deglutition Disorders - diagnosis; Deglutition Disorders - etiology; Deglutition Disorders - physiopathology; Dysphagia; Endoscopy; Female; Fiber Optic Technology; Humans; Male; Middle Aged; Penetration; Predictive Value of Tests; Prospective Studies; Respiratory Aspiration - diagnosis; Respiratory Aspiration - etiology; Sensitivity and Specificity; Signal Processing, Computer-Assisted; Sound; Stroke - complications; Stroke - diagnosis; Stroke - physiopathology
• ISSN: 1650-1977; 1651-2081
• DOI: 10.2340/16501977-0384

To perform acoustic analysis of swallowing sounds, using a microphone and a notebook computer system, in healthy subjects and patients with dysphagia affected by neurological diseases, testing the positive/negative predictive value of a pathological pattern of swallowing sounds for penetration/aspiration. Diagnostic test study, prospective, not blinded, with the penetration/aspiration evaluated by fibreoptic endoscopy of swallowing as criterion standard. Data from a previously recorded database of normal swallowing sounds for 60 healthy subjects according to gender, age, and bolus consistency was compared with those of 15 patients with dysphagia from a university hospital referral centre who were affected by various neurological diseases. Mean duration of the swallowing sounds and post-swallowing apnoea were recorded. Penetration/aspiration was verified by fibreoptic endoscopy of swallowing in all patients with dysphagia. The mean duration of swallowing sounds for a liquid bolus of 10 ml water was significantly different between patients with dysphagia and healthy patients. We also described patterns of swallowing sounds and tested the negative/positive predictive values of post-swallowing apnoea for penetration/aspiration verified by fibreoptic endoscopy of swallowing (sensitivity 0.67 (95% confidence interval 0.24-0.94); specificity 1.00 (95% confidence interval 0.56-1.00)). The proposed technique for recording and measuring swallowing sounds could be incorporated into the bedside evaluation, but it should not replace the use of more diagnostic and valuable measures.