Using electropalatographic feedback to treat the speech of a child with severe-to-profound hearing loss.

Abstract

Abstract The speech production of a 7-year-old child with severe-to-profound hearing loss and severe speech disorder was treated using visual feedback via electropalatography (EPG). The child's productions of /k/ and /t/ were treated in consonant-vowel syllables in three vowel contexts. A single-subject multiple-baseline design was used to document treatment effects and generalization. Visual inspection and multiple time-series analyses were used to assess the data. The child demonstrated a treatment effect for /k/ as measured by lingual-palatal placement and perceptual adequacy of the productions. A treatment effect for /t/ also was suggested. Generalization was observed for the production of /g/ at the syllable level, and /g/ and /k/ in monosyllabic words in the word-initial position. Generalization to other sounds and word-final positions was not evidenced. Of note was the extreme performance variability associated with the treatment. Key Words: Electropalatography, Speech Treatment, Hearing Loss, Children. Introduction The ability to develop the motor and linguistic skills for the normal production of speech typically requires a relatively intact auditory system. Audition is critical for the development of a linguistic system with its phonological performance rules and associated acoustic goals (Tye-Murray, 1992). Furthermore, recent auditory-based models of speech development and production argue that a multi-dimensional auditory perceptual space emerges during infancy and provides the basis for the development and maintenance of speech (Callan, Kent, Guenther, & Vorperian, 2000; Guenther, 1995; Perkell et al., 1995, 1997). Speech production is learned by mapping the orosensory information to acoustic-based targets (or regions) within this auditory space. So, speech impairment and reduced speech intelligibility are expected consequences of prelingual hearing loss if early and substantive intervention does not occur (Hudgins & Numbers, 1942; Smith, 1975; Yoshinaga-Itano & Sedey, 1998). Most children with hearing loss require some type of intervention if they are to speak intelligibly and in a manner acceptable to normal hearing listeners, even though the character and severity of the speech impairments vary greatly across children. Much of the variability relates to the severity of their hearing impairment, but even children with mild-to-moderate hearing loss are at risk for resonance and segmental speech problems (Elfenbein, Hardin-Jones, & Davis, 1994; Oller & Kelly, 1974; West & Weber, 1973). The speech differences of children with mild-to-moderate hearing loss typically are treated in the same manner as the speech of hearing children, but children with more severe hearing loss tend to require more aggressive and long-term treatment to become effective oral-aural communicators. Despite the acknowledged long-term need, well-controlled studies documenting speech treatment effectiveness and efficacy is limited for this population. Even in the growing cochlear implant literature, little has been reported on what behavioral treatment approaches work best with the various types of speech impairments that occur secondary to hearing loss in children. Nearly all treatment approaches applied to children with hearing loss try to stimulate optimal use of residual hearing and/or compensate for the hearing loss by developing alternate routes for input and feedback (see Pratt, 2005 and Pratt & Tye-Murray, 1997 for reviews). Implementing speech treatment through the auditory modality typically is preferred if the auditory system itself can be treated (i.e., sensory devices and auditory training) so that sufficient sensory input and feedback are accessible. However, if hearing is limited and children are unable to form or interface with a complete internal auditory mapping of the auditory space, speech production will be restricted. Furthermore, there remain a substantive number of children with hearing loss who fail to develop normal speech production and phonology skills despite appropriate and early fitting of sensory devices and adequate behavioral intervention (Blamey et al. …