no participation over the long period

It was well known that aspiration is the primary cause of an aspiration pneumonia among the dysphagia patients.

In order to predict the degree of an aspitation,video-fluoroscopic-swallowing study and fiberoptic-endoscopic swallowing evaluation have been developed, but those evaluations are invasive and allowed only in a limited condition.

In this study, as a precedent study for the non-linear analysis, voice analysis using LPC method will be evaluated. The superiority of LPC method will be compared with a spectral analysis using Jitter and Simmer as a positive control.

This clinical study will be performed prospective, positive-controlled, single-blind (i.e. assessor-blind),and single cohort clinical trial for efficacy

Inclusion Criteria:

• Patients who were referred for VFSS

Exclusion Criteria:

• Patients cannot phonate d/t tracheostomy
• Preexisting oro-laryngo-pharyngeal disease
• Patients cannot follow 1 step command
• Patients cannot maintain a phonation for 3 seconds
• Refusal of participation
• Patients who were not classified for the candidate by physicians
• Patients who coughs following drinking of 5ml normal saline