Thomas M. Gruenenfelder

Effects of word frequency, contextual diversity, and semantic distinctiveness on spoken word recognition

The relative abilities of word frequency, contextual diversity, and semantic distinctiveness to predict accuracy of spoken word recognition in noise were compared using two data sets. Word frequency is the number of times a word appears in a corpus of text. Contextual diversity is the number of different documents in which the word appears in that corpus. Semantic distinctiveness takes into account the number of different semantic contexts in which the word appears. Semantic distinctiveness and contextual diversity were both able to explain variance above and beyond that explained by word frequency, which by itself explained little unique variance.

Fundamental frequency as a cue to postvocalic consonantal voicing: Some data from speech perception and production

Several recent studies by Lehiste have reported that changes in fundamental frequency (F0) can serve as a cue to perceived vowel length and, furthermore, that the perceived lengthening of the vowel can influence perception of the voicing feature of stop consonants in syllable-final position. In Experiment 1, we replicated Lehiste’s basic results for stop consonants in final position. Experiment 2 extended these results to postvocalic fricatives. The final consonant in syllables of intermediate vowel duration was more often perceived as voiced when F0 was falling than when F0 was monotone. In Experiment 3, we examined the F0 contours produced by eight talkers before postvocalic stop consonants and fricatives in natural speech for minimal pairs of words differing in voicing. The amount of change of F0 over the vowel was no greater before voiced than voiceless consonants, suggesting that the earlier perceptual effects cannot be explained by appealing to regularities observed in the production of F0 contours in vowels preceding postvocalic consonants.

Graph‐Theoretic Properties of Networks Based on Word Association Norms: Implications for Models of Lexical Semantic Memory

We compared the ability of three different contextual models of lexical semantic memory (BEAGLE, Latent Semantic Analysis, and the Topic model) and of a simple associative model (POC) to predict the properties of semantic networks derived from word association norms. None of the semantic models were able to accurately predict all of the network properties. All three contextual models over-predicted clustering in the norms, whereas the associative model under-predicted clustering. Only a hybrid model that assumed that some of the responses were based on a contextual model and others on an associative network (POC) successfully predicted all of the network properties and predicted a words top five associates as well as or better than the better of the two constituent models. The results suggest that participants switch between a contextual representation and an associative network when generating free associations. We discuss the role that each of these representations may play in lexical semantic memory. Concordant with recent multicomponent theories of semantic memory, the associative network may encode coordinate relations between concepts (e.g., the relation between pea and bean, or between sparrow and robin), and contextual representations may be used to process information about more abstract concepts.

Typicality ratings for 893 exemplars of 93 categories

Although the typicality effect has been much studied in the semantic memory literature, typicality ratings exist for exemplars from only a very limited number of categories. This lack of ratings frequently limits the range of stimuli that can be used in investigations of the typicality effect. As an aid in stimulus construction, this paper reports typicality ratings of 893 exemplars from 93 different categories.

Fundamental frequency as a cue to postvocalic consonantal voicing: Some data from perception and production

Several recent studies by Lehiste have reported that changes in fundamental frequency (F0) can serve as a cue to perceived vowel length and, furthermore, the perceived lengthening of the vowel can influence perception of the voicing feature of stop constants in final position. In Experiment I, we replicated Lehistes basic result for stops in final position. Stimuli of intermediate vowel duration from a “bat‐bad” continuum were more often perceived as voiced (“bad”) when F0 was falling than when F0 was monotone. In Experiment II, we found the same effect for fricatives in a synthesized “cease‐seize” continuum. In Experiment III, we examined the F0 contours produced by a single talker before post‐vocalic stop consonants and fricatives in natural speech for minimal pairs of words differing on voicing. The amount of change of F0 of the vowel was no greater before than voiced than voiceless consonants though rate of change was greater before voiceless consonants due to the shorter vowel duration. Our results ...