Effects of different levels of food on the acoustic characteristics of swallowing sounds in healthy older people.

For half a century, cervical auscultation has been proposed as a classic method for screening aspiration in patients with dysphagia. However, the effects of standardized liquid viscosity and food texture on swallowing sounds are not fully understood due to the lack of uniform standardized bolus preparation. Currently, there is insufficient guidance in the literature for the appropriate liquids and foods for swallowing training, and there is also a lack of studies using acoustic signals to monitor swallowing progress continuously.Objective Based on the international dysphagia diet standardisation initiative (IDDSI) grading, we detect the effects of different levels of food on the swallowing characteristics of healthy older people, which will lay a preliminary research foundation for further early screening and rehabilitation dietary treatment of patients with dysphagia. MethodsThirty healthy older people who met the criteria were selected as the research subjects. Eight kinds of food with different levels were prepared based on the IDDSI grading standard. A throat microphone was used to collect the swallowing sounds of eating different levels of food. RavenPro1.6.0 software was used to perform sound segmentation, annotation and swallowing acoustic index measurement.ResultsThere were significant differences in the duration and peak of the power spectral density of the sound signals of different liquids and foods. As the food level increased, the duration of swallowing also increased. As the food level increased, the peak frequency density of the sound decreased, and there were statistical differences between men and women. Although IDDSI Level 4 is classified as "liquid", its acoustic characteristics approximated those of solid foods in our cohort, suggesting physiological similarity rather than advocating reclassification. It suggests that swallowing acoustic monitoring can be used for clinical screening of dysphagia, and provide a basis for long-term swallowing behavior detection and clinical management.