Assessing spoken word recognition in children who are deaf or hard of hearing: a translational approach.

Spoken word recognition tests have been part of the audiological assessment of individuals who are deaf or hard of hearing for the last 60 years. Such tests have been used to assess the effects of hearing loss on spoken word recognition and speech perception, (Hudgins, Hawkins, Karling, & Stevens, 1947; Skinner, et al., 2002), to determine cochlear implant candidacy (Gifford, Dorman, Spahr, & Bacon, 2007; Kirk, 2000a), measure cochlear implant outcomes (Dorman, Gifford, Spahr, & McKarns, 2008; Eisenberg, Kirk, Martinez, Ying, & Miyamoto, 2004; Holt, Kirk, Eisenberg, Martinez, & Campbell, 2005) and to guide the development of an individual’s aural rehabilitation programs (Eisenberg, 2007; Mackersie, 2002). In research settings, listeners who are deaf or hard of hearing may be administered spoken word recognition tests to evaluate the effectiveness of signal processing strategies (Dorman, Loizou, Kemp, & Kirk, 2000; Firszt, Holden, Reeder, & Skinner, 2009; Gifford, Olund, & Dejong, 2011; Gifford, Shallop, & Peterson, 2008; Skinner, et al., 2002), to better understand perceptual processes that support spoken word recognition (Holt, Beer, Kronenberger, Pisoni, & Lalonde, 2012; Kirk, Pisoni, & Osberger, 1995; Krull, Choi, Kirk, Prusick, & French, 2010; Loebach, Bent, & Pisoni, 2008; Loebach & Pisoni, 2008) or to identify factors that contribute to individual variability (Desjardin, Ambrose, Martinez, & Eisenberg, 2009; Geers, 2006; Pisoni, Kronenberger, Roman, & Geers, 2011). Obviously, no one test can achieve all of these aims. Thus, the choice of spoken word recognition test(s) is dictated by the information one wishes to obtain. Our test development work originally was motivated by the observation that children with cochlear implants performed poorly on traditional tests of open-set word recognition despite the fact that parents reported their children could understand some speech through listening alone. We hypothesized that traditional tests, such as the Phonetically Balanced Kindergarten Word List (PBK) (Haskins, 1949), included vocabulary that was unfamiliar to children who are deaf or hard of hearing due to the constraints imposed by phonetic balancing of test items. Furthermore, we noted some shortcomings with traditional spoken word recognition tests. First, most tests used stimuli produced by one talker in carefully articulated speech. Such tests, in which acoustic variability is highly constrained, may not accurately reflect spoken word recognition abilities under more natural listening situations. Increasing stimulus variability by introducing multiple talkers or varying speaking rate reduces spoken word recognition performance in listeners with normal hearing (Mullenix, Pisoni, & Martin, 1989; Nygaard, Sommers, & Pisoni, 1992; Sommers, Nygaard, & Pisoni, 1994) and in listeners who are deaf or hard of hearing (Kaiser, Kirk, Lachs, & Pisoni, 2003; Kirk, 2000b; Kirk, Pisoni, & Miyamoto, 1997). Secondly, although most traditional clinical tests yield descriptive information about spoken word recognition, they reveal little about the underlying perceptual and cognitive processes employed by listeners who are deaf or hard of hearing. Finally, most tradional tests utilized an auditory-only presentation format that might not adequately characterize the performance of listeners who are deaf or hard of hearing. For example, although some adults and children with sensory aids demonstrate substantial auditory-only word recognition, others obtain high levels of speech understanding only when auditory and visual speech cues are available (Bergeson, Pisoni, & Davis, 2003; Hay-McCutcheon, Pisoni, & Kirk, 2005; Kaiser, et al., 2003). Furthermore, the ability to combine and integrate auditory and visual speech information has been found to be an important predictor of speech perception benefit with a sensory aid (Bergeson & Pisoni, 2004; Bergeson, Pisoni, & Davis, 2005; Lachs, Pisoni, & Kirk, 2001b) and thus has important implications for understanding the underlying representation and processing of speech in listeners who use these devices. We saw the need to take a new, translational approach to test development – one that builds upon a body of basic and clinical research concerning spoken word recognition by listeners with normal hearing or hearing loss. Over the last 15 years, we have created a series of word and sentence recognition tests. These measures are theoretically motivated by a model of spoken word recognition and also incorporate “real-world” stimulus variability in the form multiple talkers and presentation formats. The goal of this research is to enhance our ability to estimate real-world listening ability and to predict benefit from sensory aid use in children with varying degrees of hearing loss. Below we review our past and current test development activities.