Tongue palate contact patterns of velar stops in normal adult English speakers

Abstract

This paper provides a more detailed description of normal tongue palate contact patterns for the occlusion phase of velar stops than currently exists. The study used electropalatography (EPG) to record seven normally speaking adults' contact patterns of voiceless velar stops in nine VkV contexts. A variety of EPG indices measured: per cent complete closures across the palate; place of articulation; articulatory distance between /k/ and /t/; and amount of contact. Complete EPG closure occurred in the majority (81%) of tokens. Some speakers almost always had complete closures regardless of context, whereas other speakers produced them only with high front vowels. As expected, place of articulation and amount of contact were heavily influenced by vowel context. The most fronted and most contact occurred in /i/ contexts and the most retracted and least contact in /a/ contexts. There was considerable interspeaker variability on all measures, particularly in the precise location of velar placement and articulatory distance between alveolar and velar placement. The implications for diagnosing and treating abnormal velar articulations are discussed.

Using EPG data to display articulatory separation for phoneme contrasts

“…For example, conducted a study on normal alveolar stops and found that although all the speakers produced similar "horse-shoe" spatial patterns for these targets, some speakers had more than twice as much contact as others. Studies of typical velars (Liker & Gibbon, 2008), bilabials , vowels (Gibbon, Lee, & Yuen, 2010) and affricates (Liker et al, 2007) had similar results insofar as some speakers had twice or three times more contact than others. One explanation for this variation is that the amount of contact relates to inter speaker differences in palatal shape.…”

“…A number of recent EPG studies confirm that, even in typical adults and children, there is a wide variation between speakers in EPG index values for any given target sound (Cheng, Murdoch, Goozee, & Scott, 2007;Gibbon, Yuen, Lee, & Adams, 2007;Liker & Gibbon, 2008;Liker, Gibbon, Wrench, & Horga, 2007;McLeod, Roberts, & Sita, 2006). For example, conducted a study on normal alveolar stops and found that although all the speakers produced similar "horse-shoe" spatial patterns for these targets, some speakers had more than twice as much contact as others.…”

Between-word processes in children with speech difficulties: insights from a usage-based approach to phonology

“…Despite gaps in tongue-palate contact in the velar region, it is possible that the tongue body raising gesture occurred but could not be measured by EPG alone. Liker and Gibbon (2008) suggest that closure does occur in these cases but in a location posterior to the area covered by the EPG electrodes. It is also possible, of course, that the incomplete closure observed in the linguapalatal contact patterns indicates a laxer articulation of the velar consonant.…”

“…It has been suggested that instances of partial assimilation in normal adult speech involve a reduced coronal gesture which results in the lateral contact with the hard palate observed here (Ellis and Hardcastle, 2002). The retracted production of velar plosives has been observed in connected speech in adults in both single syllable production (Liker and Gibbon, 2008) and connected speech (Hardcastle, 1994), and in other children with speech difficulties (Howard, 2004) and is likely to reflect inter-and intra-speaker variation. Despite gaps in tongue-palate contact in the velar region, it is possible that the tongue body raising gesture occurred but could not be measured by EPG alone.…”

Tongue-Palate Contact during Selected Vowels in Normal Speech

“…It is desirable to have multiple repetitions of speech material due to intra-speaker variability and to record an adequately sized group of speakers due to inter-speaker variability. In terms of variability in amount of contact, recent studies have shown that although typical speakers produce similar contact patterns for target sounds, some speakers can have up to twice as much contact as others (Cheng et al, 2007;Liker et al, 2007;Liker and Gibbon, 2008).…”