## 1 Introduction
Further, a closed set response format may be influenced by a variety of lexical (e.g., potential ambiguity of a target word, etc. ), semantic or contextual factors [39], and/or aspects of word familiarity, even in simple listening paradigms [40], or the naturalness of sound sequences within target words [41]. This limitation in whole-word scoring has led some investigators to explore accuracy assessment options through use of nonsense stimuli across a variety of communication disorders [10; 42; 43; 44; 45]. In contrast to closed-set response paradigms, an open-set response model requires that listeners are not placed in a \"forced-choice\" auditory-perceptual situation. Rather, in an open-set paradigm, listener responses may provide a more representative index of what they perceived, and, consequently, their composite accuracy scores may be more representative of production/perceptual errors [35]. While whole-word intelligibility scoring is valuable, phonemic scoring may provide a more representative measure of accuracy in that it may avoid inflated perceptual identifications (i.e., accuracy scores) using something that may mirror a \"cloze\" procedure typically associated with reading [46]. In such a circumstance, partial perceptions of a target word may allow the listener to make judgments of the entire stimulus without full detection of each specific sound. The task of detecting the target may be further influenced by contextual factors, word frequency, and/or probabilistic \"guessing\", an unintended consequence that may aid the \"correct\" detection of a target word by the listener despite the speaker's inaccurate production of one or more phonemes within the word. This may be particularly important in quantifying the production challenges of TE speakers, given the unique voicing challenges that they have been shown to demonstrate [10; 15]. While we are most interested in listener perceptions of TE speech, we are keenly aware that listener judgments are directly influenced by production errors. Thus, the use of the term \"production/perceptual\" errors may better represent the data to be presented within this work. For example, intrinsic methods of postlarynectomy voice production (i.e., TE and esophageal speech) are frequently characterized by voiced-for-voiceless sound errors across a range of phonetic categories, such as stops, fricatives, etc. [16; 47]. Because the tracheoesophageal voicing source is not an adductor-abductor mechanism, changes in fine voice control and the associated changes in the acoustic signal secondary to this limitation may have collective influences on the accuracy of speech production. Thus, the use of a more refined method of phonemic scoring in conjunction with an open-set response paradigm may provide a more comprehensive measure of speaker performance and change over time, regardless of the underlying voice and/or speech disorder [43]. Additionally, employing an open-set response paradigm for listeners may address critical clinical concerns in that more specific information related to the nature of a given speaker's speech production errors may be obtained. This type of detailed speech production data may support the development of a treatment framework directed at improving overall intelligibility. However, while phonemic scoring can benefit intelligibility assessments, it also raises concerns specific to the construction of stimulus materials and how this may influence accuracy scores obtained from normal hearing listeners [48]. Although not without limitations and/or the potential for perceptual bias, use of normal-hearing listeners may provide the opportunity to more accurately identify production accuracy of disordered speakers. Further, our interest in the potential influence of phonetic construction of each list was guided by clear differences in sound representation across these lists.