H impairments [20] as well as significant correlations between at least one of the measures applied here (nPVI-V) and perceptual ratings of disordered speakers [28]. On the other hand, they confirm Kim et al.’s [27] findings, as these authors also failed to differentiate disordered from healthy speakers with their PVI measure. Small sample size and intra-group variability are frequently cited as reasons for lack of statistical significance, both of which can be said to apply in this study. There is certainly a possibility that a larger sample group would have resulted in more affirmative group differences for the rhythm metrics. In addition, one could argue that the highly repetitive nature of the task might have influenced results in some way, leading to a loss of distinction between speakers groups. The results reported by Henrich et al. [28] could support this conclusion as they also observed that groups differed from each other in some but not other tasks. Irrespective of these explanations, the issue remains that there was a considerable mismatch between the acoustic and perceptual analysis. More importantly, this study identified a number of issues that appeared to affect the way rhythmic deviations were captured by the metrics. These would apply even in cases where these metrics did highlight differences to healthy speakers, and it is thus important to consider them in future research as well as clinical practice. Two patterns in particular were identified in the sentence repetition as well as the spontaneous speech task: changes to vowel duration and segment deletion. As already described in the Results section, they both caused changes to the normal speech timing pattern, however, they could not be captured equally well by the metrics. The effects of segment deletion, resulting in the proliferation of stressed syllables and thus less durational differences between successive vowels, should become apparent in the rhythm metrics. On the other hand, the observed changes to vowel changes can have a more serious effect on rhythm measures, particularly if the speaker is so severely impaired that the normal timing relationships are reversed. Rhythm metrics solely focus on the duration of vowels, irrespective of whether their relative timing is correct or not, hence they might yield results within the normal range even in cases where speakers are producing highly inappropriate patterns. It should be noted that none of the speakers produced exclusively one or the other of the described speech deviances, and parts of the utterance were always produced correctly. This could be another contributing reason why the rhythm metrics did not show the expected group differences as the effects of the various types of speech deviations on the metrics cancelled each other out. While there are currently no other published clinical data available to my knowledge that report on mismatches between acoustic and perceptual results, there are some parallels from findings in cross-linguistic investigations of rhythm. Arvaniti[39] observed that different types of accented English were classified into the same rhythm category despite diverse speech patterns, e.g. English materials spoken by native Korean and Spanish speakers were both classified as syllable timed according to the rhythm metric results, but this was attributable to phrase-final HMPL-012 web lengthening by Korean speakers as opposed to lenition of intervocalic consonants by Spanish (��)-Zanubrutinib site participants. Both the cu.H impairments [20] as well as significant correlations between at least one of the measures applied here (nPVI-V) and perceptual ratings of disordered speakers [28]. On the other hand, they confirm Kim et al.’s [27] findings, as these authors also failed to differentiate disordered from healthy speakers with their PVI measure. Small sample size and intra-group variability are frequently cited as reasons for lack of statistical significance, both of which can be said to apply in this study. There is certainly a possibility that a larger sample group would have resulted in more affirmative group differences for the rhythm metrics. In addition, one could argue that the highly repetitive nature of the task might have influenced results in some way, leading to a loss of distinction between speakers groups. The results reported by Henrich et al. [28] could support this conclusion as they also observed that groups differed from each other in some but not other tasks. Irrespective of these explanations, the issue remains that there was a considerable mismatch between the acoustic and perceptual analysis. More importantly, this study identified a number of issues that appeared to affect the way rhythmic deviations were captured by the metrics. These would apply even in cases where these metrics did highlight differences to healthy speakers, and it is thus important to consider them in future research as well as clinical practice. Two patterns in particular were identified in the sentence repetition as well as the spontaneous speech task: changes to vowel duration and segment deletion. As already described in the Results section, they both caused changes to the normal speech timing pattern, however, they could not be captured equally well by the metrics. The effects of segment deletion, resulting in the proliferation of stressed syllables and thus less durational differences between successive vowels, should become apparent in the rhythm metrics. On the other hand, the observed changes to vowel changes can have a more serious effect on rhythm measures, particularly if the speaker is so severely impaired that the normal timing relationships are reversed. Rhythm metrics solely focus on the duration of vowels, irrespective of whether their relative timing is correct or not, hence they might yield results within the normal range even in cases where speakers are producing highly inappropriate patterns. It should be noted that none of the speakers produced exclusively one or the other of the described speech deviances, and parts of the utterance were always produced correctly. This could be another contributing reason why the rhythm metrics did not show the expected group differences as the effects of the various types of speech deviations on the metrics cancelled each other out. While there are currently no other published clinical data available to my knowledge that report on mismatches between acoustic and perceptual results, there are some parallels from findings in cross-linguistic investigations of rhythm. Arvaniti[39] observed that different types of accented English were classified into the same rhythm category despite diverse speech patterns, e.g. English materials spoken by native Korean and Spanish speakers were both classified as syllable timed according to the rhythm metric results, but this was attributable to phrase-final lengthening by Korean speakers as opposed to lenition of intervocalic consonants by Spanish participants. Both the cu.