Measuring Articulation Rate: A Comparison of Two Methods.

ABSTRACT

PURPOSE: Mean articulatory rate (MAR) is an alternative approach to measure articulation rate and is defined as the mean of 5 rate measures in minimally 10 to maximally 20 consecutive syllables in perceptually fluent speech without pauses. This study examined the validity of this approach. METHOD: Reading and spontaneous speech samples were collected from 80 typically fluent adults ranging in age between 20 and 59 years. After orthographic transcription, all samples were subjected to an articulation rate analysis first using the prevailing "global" method, which takes into account the entire speech sample and involves manipulation of the speech sample, and then again applying the MAR method. Paired-samples t tests were conducted to compare global measurements to MAR measurements. RESULTS: For both spontaneous speech and reading, a strong correlation was found between the 2 methods. However, for both speech tasks, the paired-samples t tests revealed a significant difference with MAR values being higher than the global method values. CONCLUSIONS: The MAR method is a valid method to measure articulation rate. However, it cannot be used interchangeably with the prevailing global method. Further standardization of the MAR method is needed before general clinical use can be suggested.