Turkish Journal of Physical Medicine and Rehabilitation 2007 , Vol 53 , Num 3
Effects of Age, Gender, Bolus Volume and Viscosity on Acoustic Signals of Normal Swallowing
Sibel Eyigör 1 ,Adrienne L. Perlman 2 ,Xuming HE 3
1 Department of Physical Medicine and Rehabilitation, Ege University Faculty of Medicine, İzmir, Turkey
2 Ege Üniversitesi Tıp Fakültesi, Konuşma ve İşitme Bilim Dalı, Bornova, Izmir, Türkiye
3 Department of Statistics, University of IIIinois at Urbana-Champaign, IIIinois, USA

Objective: The purpose of this investigation was to determine the effects of age, gender, bolus volume and bolus viscosity on the acoustic signals of normal swallows.  

Materials and Methods: Healthy volunteers (n=146) ranging from 3 to 85 years of age participated in the investigation. Subjects were grouped by age: 3-5, 18-25 and 70-85 years of age.  Subjects performed a series of swallows that were randomized according to volume and viscosity.  A total of 3056 swallows were analyzed. Four temporal events were compared; acoustic onset, acoustic peak, acoustic spike associated with the small non-inspiratory flow, and acoustic offset.  

Results: In the youngest group, a significant effect was found for volume, viscosity and gender for the time of acoustic onset (p<0.01).  In the 
oldest age group, the variability for acoustic onset was much higher than in the other age groups (p<0.01).  The oldest group had a substantially longer acoustic duration, especially for men (p<0.01). Additionally,  a significant effect for viscosity and volume for the time of acoustic offset was found in the oldest age group (p<0.01). 

Conclusion: During normal swallowing, it was determined the effects of age, gender, bolus volume, and bolus viscosity on the acoustic signals of normal swallow.

Keywords : Swallowing, acoustic signal, age, gender, bolus volume, bolus viscosity