The Effect of Procedural Variations on Maximum Phonation Time in Young Adult Females

Aim: The aim of this study was to investigate procedural impacts on Maximum Phonation Time (MPT), a popular non-standardised voice assessment. The study compared the MPT measured by a stopwatch and an offline measurement from an audio-recording. The study also investigated the effect of a demonstration on participants' mean, greatest and first trial phonation duration, as well as the effect of the demonstration on the amount of variation between participants and on the trial number yielding the greatest duration. The effect of the trial number on duration in both groups was investigated. The amount of variation in the researcher's demonstration and the effect of demonstration duration on participants' mean, greatest and first trial duration were also investigated. Method: 33 females between 19 and 25 years old were recruited and randomly allocated either the Model or No Model group. Participants prolonged [a] for as long as possible 5 times and their durations were measured live using a stopwatch and offline using the computer programme Praat (Boersma and Weeink 2013). Statistical analysis was then used to investigate if there were significant differences in any of the variables being explored. Results: The results showed a large amount of intrapersonal and interpersonal variation. There was a very high correlation between the stopwatch and audio-recording measurements. There was no significant difference between the Model and No Model groups' mean, greatest or first trial duration, but the Model Group showed significantly less variation between participants. The use of a demonstration did not result in greatest MPT being achieved in an earlier trial. Trial 5 was significantly longer than trial 1, with most of the increase being in the first few trials. The researcher's demonstration was quite long compared to most participants, and was quite, but not particularly variable. The demonstration duration did not have a significant effect on participants' mean, greatest or first trial duration. Conclusion: The procedural factors investigated do not vastly skew MPT results, but the study provides clinicians with information on aspects of the MPT assessment which should be kept consistent. Other apparent impacts on MPT were identified, including personal factors, environmental factors, and other procedural factors regarding ensuring participants perform the absolute maximum phonation duration of which they are capable.bsc_Speunpub2516_ethesesunpu