Normal swallowing acoustics across age, gender, bolus viscosity, and bolus volume.

Cervical auscultation has been proposed as an augmentative procedure for the subjective clinical swallowing examination due to the tangible differences between normal and dysphagic swallowing sounds. However, the research is incomplete regarding cervical auscultation and swallowing acoustics in that the differences between the sounds of normal versus dysphagic swallowing have yet to be fully understood or quantified. The swallows of 96 reportedly healthy adults, balanced for gender and divided into younger, middle, and older age groups, were audio-recorded while ingesting several boluses of varying viscosity and volume. The audio signals were then analyzed to determine their temporal and acoustic characteristics. Results indicated increasing pharyngeal swallowing duration with increasing age, bolus viscosity, and bolus volume. In addition, an increased duration to peak intensity with increasing age was found in one of our two analyses, as well as with some of the more viscous versus less viscous boluses. Men and older persons produced higher peak intensities and peak frequencies than women and younger persons. Thin liquids were produced with more intensity than honey or more viscous boluses, and with greater frequency than mechanical soft solids. Larger volumes resulted in greater peak frequency values. Some of the acoustic measurements appear to be more useful than others, including the duration of the acoustic swallowing signal and the within-subjects peak intensity variable. We noted that differences in swallowing acoustics were more related to changes in viscosity rather than volume. Finally, within-participant observations were more useful than between-participant observations.

Script training treatment for adults with apraxia of speech.

PURPOSE: Outcomes of script training for individuals with apraxia of speech (AOS) and mild anomic aphasia were investigated. Script training is a functional treatment that has been successful for individuals with aphasia but has not been applied to individuals with AOS. Principles of motor learning were incorporated into training to promote long-term retention of scripts. METHOD: Three individuals with AOS completed script training. A multiple-baseline, across-behaviors design examined acquisition of client-selected scripts. Errors and speaking rates were also analyzed. Random practice and delayed feedback were incorporated into training to promote motor learning. Probes for long-term retention were elicited up to 6 months after treatment. RESULTS: All clients successfully acquired their scripts, and probes demonstrated script retention 6 months after treatment. Errors generally decreased but remained variable even during maintenance and retention probes. Speaking rate increased for 2 clients but also remained variable. CONCLUSIONS: Script training was successful and functional for clients with AOS. Clients reported increased confidence, speaking ease, and speech naturalness. Although scripts did not become errorless, clients retained their scripts and reported using them frequently. Whether principles of motor learning may have promoted the long-term retention of scripts exhibited by participants must be determined through future research.

Differences in tongue strength across age and gender: is there a diminished strength reserve?

Maximum tongue strength was investigated and compared to mean swallowing pressure elicited by the anterior tongue to calculate the percentage of maximum tongue strength used during swallowing in 96 participants with normal swallowing, divided into three 20-year age groups. The purposes of this investigation were to investigate normal swallowing physiology and to determine whether tongue strength reserves diminished according to age or gender. The results of the study yielded significant maximum tongue strength differences between the youngest and oldest and middle and oldest age groups; the oldest group had the weakest tongues. Mean swallowing pressure did not differ based on age, but women were found to have significantly higher pressures than men. The percentage of maximum tongue strength used during swallowing did not vary as a function of age, but women used a significantly higher percentage of tongue strength to swallow than men. Based on the results, it appears that a diminishing strength reserve does not exist based on age, but it does exist based on gender. Specifically, it appears that women have a reduced tongue strength reserve compared to men. Clinical implications are discussed.

Tongue measures in individuals with normal and impaired swallowing.

PURPOSE: This investigation sought to add to the extant literature on measures of normal tongue function, to provide information on measures of tongue function in a group of individuals with oral phase dysphagia, and to provide a comparison of these 2 groups matched for age and gender. METHOD: The Iowa Oral Performance Instrument was utilized to measure tongue function (strength and endurance) in a group of individuals with normal (N=200) and impaired (N=50) swallowing. The peak measure of 3 encouraged trials was recorded as participants' strength, and 50% of their peak was sustained as long as possible for endurance. RESULTS: Results for the control group supported previous investigations wherein greater tongue strength was found in males than in females and in the youngest versus oldest groups. The experimental group demonstrated a similar trend in strength for gender. When matched for age and gender, the experimental group demonstrated significantly lower strength. Significant differences were not revealed on measures of tongue endurance. CONCLUSIONS: We were able to extend the normative database on tongue function and document reduced tongue strength in a group of individuals with dysphagia. The findings provide evidence that in this group, tongue weakness coincided with signs of dysphagia, adding justification for tongue-strengthening protocols.

Measures of tongue function related to normal swallowing.

The availability of objective measures of tongue function presents a possible supplement to the clinical dysphagia evaluation. The purpose of this study was to improve our understanding of normal tongue physiology during swallowing and maximum isometric tasks, establish a preliminary database of tongue function variables, and determine if differences existed among the variables as a function of age, gender, or varied bolus consistency. Ninety subjects, divided into age and gender groups, participated in tasks that determined maximum isometric tongue pressure, mean tongue pressure during swallowing, and percentage of maximum isometric pressure used during swallowing. Descriptive statistics, correlations, and analyses of variance were computed to analyze the data. Results indicated that males had significantly higher maximum isometric pressures than females, and the youngest group had significantly higher maximum pressures than the oldest group. Mean swallowing pressures and percentage of maximum isometric pressures used during swallowing differed as a function of bolus type but did not differ as a function of age or gender. In addition, maximum isometric pressures were correlated with mean swallowing pressures, and mean swallowing pressures and percentage of maximum isometric pressures used during swallowing were correlated between consistencies.

An acoustic profile of normal swallowing.

Cervical auscultation has been proposed as a technique to augment the clinical evaluation of dysphagia to improve its accuracy in the diagnosis of dysphagia. Before using cervical auscultation to reliably diagnose disordered swallowing, it is necessary to first acoustically characterize normal swallowing for comparison with dysphagic swallowing. Ninety-seven healthy adult participants consumed teaspoon boluses of various consistencies while the sounds of swallowing were recorded. Descriptive statistics were reported for measures of duration, intensity, and frequency of the acoustic swallowing signal. Correlations between the variables and between bolus consistencies were computed. Overall, results compared favorably with previous research. Significant correlations were found among several of the variables, including an increasing duration of the acoustic swallowing signal with increasing age and decreasing intensity of the signal with increasing age. None of the variables differed significantly as a function of gender. Of potential clinical relevance, significant correlations between bolus consistencies for the duration and intensity variables indicated relative similarities across bolus consistencies. Duration and intensity of the acoustic signal appeared to be the most reliable of the variables measured. These results could serve as a reference point for future studies into normal swallowing across multiple bolus consistencies and volumes and eventually be compared with disordered swallowing.