Does Tonal Speech Error Exist in Taiwanese Mandarin Speakers? A Study Using Tonguetwisters both in Inner and Overt Speech.

The current study is set to investigate two debates. First, it has been controversial whether Mandarin tone representation is independent from segments in phonological encoding (e.g., Wan & Jaegar, 1998, 2003; Wan, 2007b) or dependently like lexical stress (e.g., Chen, 1999; Chen, Chen, & Dell, 2002). Secondly, previous studies had different views at whether inner speech is as feature-specified as overt speech (e.g., Corley, Brocklehurst, and Moat, 2011; Oppenheim & Dell, 2008, 2010, 2012), in which the core is the existence of phonemic similarity effect in inner slips and its size. Therefore, we employed a self-report-error tonguetwister paradigm (adapted from Brocklehurst & Corley, 2011) in inner and overt speech, comparing native Taiwanese Mandarin speakers’ tonal and segmental errors in the following Match/Mismatch (Tone × Syllable) conditions: (1) tone × syllable match; (2) tone mismatch; (3) syllable mismatch; (4) tone × syllable mismatch.Although we preliminarily confirmed tonal error exists both in overt and inner speech, its amount in inner speech (only 7 of 197 slips) was rare, which limited our inferential analysis. Secondly, in the mixed-effect regression models, we found significant effect from syllable match/mismatch in predicting overt speech errors (i.e, segmental and tonal) and inner segmental errors, but not in tone match/ mismatch effect on error likelihoods. This suggested that tone conditions are not as influential as segments to speech errors, which might support Chen’s theses. Also, the presence of syllable match/mismatch effect in inner and overt segmental errors proved that phonemic similarity effect is shared in inner and overt Mandarin speech, implying that Mandarin inner speech is as feature-specified as overt speech, and this might reject some findings from Indo-European languages that inner speech is impoverished at feature level (e.g., Oppenheim & Dell, 2008, 2010, 2012). Details about the reason were discussed