Acoustic analysis of clear versus conversational speech in individuals with Parkinson disease

Clear Speech Variants: An Acoustic Study in Parkinson's Disease

“…Many of the same segmental and suprasegmental acoustic adjustments produced by healthy speakers have also been reported in the few published clear speech studies of dysarthria (Goberman & Elmer, 2005;Tjaden et al, 2013;Whitfield & Goberman, 2014). In these studies, the majority of speakers with PD increased VSA in clear relative to conversational speech.…”

“…Last, a variety of studies have reported rate abnormalities in PD (Canter, 1963(Canter, , 1965Flint et al, 1992;Hammen & Yorkston, 1996;Ludlow & Bassich, 1983;Metter & Hanson, 1986;Solomon & Hixon, 1993;Skodda & Schlegel, 2008), although other studies reported no differences in rate relative to healthy controls (Ackermann & Ziegler, 1991;Caligiuri, 1989;Goberman et al, 2002). It is interesting to note that speakers with PD can compensate for some of the diseaserelated changes in production using speech clarity techniques, resulting in a reduced articulation rate, increased F0 variability, increased VSA, and increased SPL (Dromey, 2000;Goberman & Elmer, 2005;Tjaden et al, 2013;Tjaden, Richards, Kuo, Wilding, & Sussman, 2014;. Thus, as elaborated in the following section, clear speech appears to hold promise as a therapy technique for addressing the speech impairment in PD.…”

“…For example, relative to healthy controls, speakers with PD produce more centralized vowel space areas (VSAs; Liu, Tsao, & Kuhl, 2005;Tjaden, Lam, & Wilding, 2013;Turner, Tjaden, & Weismer, 1995;Weismer, Jeng, Laures, Kent, & Kent, 2001), less spectrally distinct consonants (Tjaden & Wilding, 2004), weakened or less precise stop closures (Ackermann & Ziegler, 1991), and shallower second formant (F2) slopes, indicating slowed changes in vocal tract adjustments (Kent & Adams, 1989;Kim, Kent, & Weismer, 2011;Walsh & Smith, 2011). At the suprasegmental level, speakers with PD tend to pause more often (Torp & Hammen, 2000; but see Goberman & Elmer, 2005), utilize an increased fundamental frequency (F0; Canter, 1963;Goberman, Coelho, & Robb, 2002), and exhibit decreased variability in F0 (Canter, 1963(Canter, , 1965Flint, Black, Campbell-Taylor, Gailey, & Levinton, 1992;Skodda, Visser, & Schlegel, 2011a). Some studies have also reported reduced sound pressure levels (SPLs; Fox & Ramig, 1997;Skodda, Visser, & Schlegel, 2011b;Tjaden et al, 2013;Walsh & Smith, 2011).…”

“…In these studies, the majority of speakers with PD increased VSA in clear relative to conversational speech. A clear speech technique can also help speakers with PD produce increased vocal intensity, increased spectral change, higher mean F0, greater F0 variation, and slower articulation rates (Dromey, 2000;Goberman & Elmer, 2005;. Clear speech therefore appears to be a feasible therapeutic strategy for addressing speech impairment secondary to PD.…”

Listener Perception of Monopitch, Naturalness, and Intelligibility for Speakers With Parkinson's Disease

“…Such approaches can be categorized into those that use biofeedback (e.g., speech intensity; Rubow & Swift, 1985); devices (e.g., voice amplifiers; Greene & Watson, 1968); masking (Adams & Lang, 1992;Ho, Bradshaw, Iansek, & Alfredson, 1999;Stathopoulos et al, 2014); behavioral voice treatments, such as rate reduction (Duffy, 1995;Lowit, Dobinson, Timmins, Howell, & Kröger, 2010); delayed auditory feedback (Hanson & Metter, 1983); clear speech (Goberman & Elmer, 2005); targeted respiratory exercises (Baumgartner, Sapir, & Ramig, 2001;Ramig, Countryman, Thompson, & Horii, 1995); and Lee-Silverman Voice Treatment (Ramig, Bonitati, Lemke, & Horii, 1994;Ramig, Fox, & Sapir, 2004. A large number of studies have reported overall improvements in speech intensity, voice quality, articulation, and speech intelligibility (Baumgartner et al, 2001;Cannito et al, 2012;Fox et al, 2006;Ramig et al, 1994Ramig et al, , 1995Ramig et al, , 2001Sapir, Spielman, Ramig, Story, & Fox, 2007;Trail et al, 2005), but the effects of these treatments on speech naturalness has not been investigated.…”