Speech intelligibility tests in noise have become a standard in hearing diagnostics and in assessing rehabilitation outcomes (Minimum speech test battery for adult cochlear implant users, 2011; Uhler et al., 2017).
However, the majority of speech intelligibility tests in noise are designed for and evaluated with working-aged adults (Nilsson, Soli and Sullivan, 1994; Wagener, Brand and Kollmeier, 1999a; Wagener, Kühnel and Kollmeier, 1999; Spahr et al., 2012). Since the ability to perceive speech in noise is still developing in primary-school-aged children (Stuart, 2005;
Corbin et al., 2016; Buss et al., 2019; Leibold and Buss, 2019), and as language delays may limit the vocabulary of hearing-impaired children (Tomblin et al., 2015; Walker et al., 2015; Cupples et al., 2018; Percy-Smith et al., 2018), the speech intelligibility tests in noise commonly used with adults may not be as reliable in pediatric diagnostics (Wagener and Brand, 2005; Holder, Sheffield and Gifford, 2016). The need for age-appropriate speech intelligibility tests in noise for children is well recognized (Bagatto et al., 2011; Uhler et al., 2017). Several simplified versions of commonly used speech audiometric tests have been developed: Hearing in Noise Test for Children (HINT-C, Nilsson, Soli, and Gelnett 1996), a pediatric version of the original Hearing in Noise Test (HINT, (Nilsson, Soli and Sullivan, 1994)), BabyBio (Spahr et al., 2014) based on the AzBio Sentences (Spahr et al., 2012) and OLKISA (Oldenburger Kinder-Satztest / Oldenburg Sentence Test for Children, (Wagener and Kollmeier, 2005)) based on the
OLSA (Oldenburger Satztest / Oldenburg Sentence Test, (Wagener, Brand
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and Kollmeier, 1999b, 1999a; Wagener, Kühnel and Kollmeier, 1999)), a German matrix sentence test (Kollmeier et al., 2015).
Age adversely affects speech recognition in noise also at the other end of the age spectrum. Multiple studies have shown that aging and cognitive decline affect the ability to understand speech in noise independently of hearing level (Dubno, Dirks and Morgan, 1984; Pichora‐Fuller, Schneider and Daneman, 1995; Dubno, 2015; Füllgrabe, Moore and Stone, 2015;
Goossens et al., 2017; Buss et al., 2019). Therefore, test procedures that provide reliable and repeatable results in working-age adults may not be well suited for all elderly patients. For example, the use of everyday sentences over single words as a test material is usually encouraged since sentences better represent everyday listening situations. The use of sentence-level test material, especially if additional practice lists are
included to familiarize the test subjects with the test procedure and speech material (Nilsson, Soli and Sullivan, 1994; Spahr et al., 2012; Kollmeier et al., 2015), may lead to test procedures that are too long and cognitively
demanding for some elderly patients. The use of simplified speech intelligibility tests is well established in pediatric audiology, but to our knowledge, no studies have assessed the applicability of simplified (pediatric) speech intelligibility tests in the elderly.
The first aim of our study was to develop a simple Finnish speech intelligibility test in noise that could be used both with children and with the elderly. Since the most widely used, and the only internationally comparable diagnostic speech intelligibility test in noise in the Finnish language, is the Finnish matrix sentence test (FMST, (Dietz et al., 2014, 2015)), it was logical to base the new test on the FMST.
The FMST is one of the tests in the growing matrix sentence test family that is based on the Hagerman matrix sentences (Hagerman, 1982), and on a test construction and protocol first introduced with the OLSA (Wagener, Brand and Kollmeier, 1999a, 1999b; Wagener, Kühnel and Kollmeier, 1999). These type of matrix sentence tests (referred to simply as “matrix tests” in this paper from
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here on) use a matrix of 50 everyday words to form five-word sentences that have a fixed and grammatically correct structure but semantically unpredictable content (e.g., ‘Sofia sees five red cars.’ or ‘Harri buys two small cups.’). During a routine test procedure, the sentences are presented against a quasi-random speech-shaped background noise that is kept at a fixed level while the presentation level of the sentences varies in an adaptive manner.
The first simplified version of the matrix test, OLKISA (Wagener and Kollmeier, 2005) was based on the German matrix test (Wagener, Brand and Kollmeier, 1999a, 1999b; Wagener, Kühnel and Kollmeier, 1999). The OLKISA uses a test procedure similar to the matrix tests, but the test material is simpler comprising three-word pseudo-sentences (e.g., three red cars)
compiled from a word matrix of 21 words (Wagener and Kollmeier, 2005). The test procedure is also shorter, as one test list contains only 14 pseudo-
sentences instead of the 20 or 30 sentences used in the typical matrix test protocol (Kollmeier et al., 2015). The OLKISA has been validated in noise (Wagener and Kollmeier, 2005) and in quiet (Wagener and Kollmeier, 2005;
Neumann et al., 2012) with normal-hearing children, and it has been studied in hearing-impaired (HI) children in quiet (Ebner, Steffens and Hellbrück, 2008;
Weißgerber et al., 2012) and in noise (Ebner, Steffens and Hellbrück, 2008). In these studies, the OLKISA was found more suitable than the OLSA when testing normal-hearing (NH) children aged 6-8 (Wagener and Kollmeier, 2005) and considered appropriate for HI children in noise and in quiet (Ebner, Steffens and Hellbrück, 2008; Weißgerber et al., 2012). The OLKISA has been evaluated in NH young adults (YA) (Buschermöhle, Wagener and Kollmeier, 2016) (Buschermöhle, Wagener, and Kollmeier 2016), but we found no published studies on the OLKISA or any other simplified matrix test in elderly patients.
The aim of our first study was to develop the Finnish simplified matrix sentence test (FINSIMAT) according to the model provided by the OLKISA, and to evaluate the new test with NH YAs. The aim of our second study was to evaluate the newly developed FINSIMAT in elderly patients with mild to
moderate hearing impairment, and to test if any systematic differences can be
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found between the FINSIMAT and the FMST results in this group of elderly patients.
5.3 STUDY 1: THE DEVELOPMENT AND EVALUATION OF THE