Phonological Neighborhood Research Articles

K-SPAN: A lexical database of Korean surface phonetic forms and phonological neighborhood density statistics.

This article presents K-SPAN (Korean Surface Phonetics and Neighborhoods), a database of surface phonetic forms and several measures of phonological neighborhood density for 63,836 Korean words. Currently publicly available Korean corpora are limited by the fact that they only provide orthographic representations in Hangeul, which is problematic since phonetic forms in Korean cannot be reliably predicted from orthographic forms. We describe the method used to derive the surface phonetic forms from a publicly available orthographic corpus of Korean, and report on several statistics calculated using this database; namely, segment unigram frequencies, which are compared to previously reported results, along with segment-based and syllable-based neighborhood density statistics for three types of representation: an "orthographic" form, which is a quasi-phonological representation, a "conservative" form, which maintains all known contrasts, and a "modern" form, which represents the pronunciation of contemporary Seoul Korean. These representations are rendered in an ASCII-encoded scheme, which allows users to query the corpus without having to read Korean orthography, and permits the calculation of a wide range of phonological measures.

The influence of lexical characteristics and talker accent on the recognition of English words by speakers of Japanese.

Whether or not the influence of listeners' language proficiency on L2 speech recognition was affected by the structure of the lexicon was examined. This specific experiment examined the effect of word frequency (WF) and phonological neighborhood density (PND) on word recognition in native speakers of English and second-language (L2) speakers of English whose first language was Japanese. The stimuli included English words produced by a native speaker of English and English words produced by a native speaker of Japanese (i.e., with Japanese-accented English). The experiment was inspired by the finding of Imai, Flege, and Walley [(2005). J. Acoust. Soc. Am. 117, 896-907] that the influence of talker accent on speech intelligibility for L2 learners of English whose L1 is Spanish varies as a function of words' PND. In the currently study, significant interactions between stimulus accentedness and listener group on the accuracy and speed of spoken word recognition were found, as were significant effects of PND and WF on word-recognition accuracy. However, no significant three-way interaction among stimulus talker, listener group, and PND on either measure was found. Results are discussed in light of recent findings on cross-linguistic differences in the nature of the effects of PND on L2 phonological and lexical processing.

Phonological neighbors and phonetic realizations of Korean word-initial bilabial and alveolar stops

Phonological neighbors and phonetic realizations of Korean word-initial bilabial and alveolar stops

What makes a word easy to acquire? The effects of word class, frequency, imageability and phonological neighbourhood density on lexical development

This article analyses how a set of psycholinguistic factors may account for children’s lexical development. Age of acquisition is compared to a measure of lexical development based on vocabulary size rather than age, and robust regression models are used to assess the individual and joint effects of word class, frequency, imageability and phonological neighbourhood density on Norwegian children’s early lexical development. The Norwegian Communicative Development Inventories (CDI) norms were used to calculate each CDI word’s age of acquisition and vocabulary size of acquisition. Lexical properties were downloaded from the lexical database Norwegian Words, supplemented with data on frequency in adult and child-directed speech. Age of acquisition correlated highly with vocabulary size of acquisition, but the new measure was more evenly distributed and more sensitive to lexical effects. Frequency in child-directed speech was the most important predictor of lexical development, followed by imageability, which seems to account for the dominance of nominals over predicates in Norwegian.

Targeted memory reactivation of newly learned words during sleep triggers REM-mediated integration of new memories and existing knowledge

Recent memories are spontaneously reactivated during sleep, leading to their gradual strengthening. Whether reactivation also mediates the integration of new memories with existing knowledge is unknown. We used targeted memory reactivation (TMR) during slow-wave sleep (SWS) to selectively cue reactivation of newly learned spoken words. While integration of new words into their phonological neighbourhood was observed in both cued and uncued words after sleep, TMR-triggered integration was predicted by the time spent in rapid eye movement (REM) sleep. These data support complementary roles for SWS and REM in memory consolidation.

The influence of lexical factors on vowel distinctiveness: Effects of jaw positioning

The phonetic characteristics of words are influenced by lexical characteristics, including word frequency and phonological neighborhood density (Baese-Berke & Goldrick, 2009; Wright, 2004). In our previous research, we replicated this effect with neurologically healthy young adults (Munson & Solomon, 2004). In research with the same set of participants, we showed that speech sounded less natural when produced with bite blocks than with an unconstrained jaw (Solomon, Makashay, & Munson, 2016). The current study combined these concepts to examine whether a bite-block perturbation exaggerated or reduced the effects of lexical factors on normal speech. Ten young adults produced more challenging lexical stimuli (i.e. infrequent words with many phonological neighbors) with shorter vowels and more disperse F1/F2 spaces than less challenging words (i.e. frequent words with few phonological neighbors). This difference was exaggerated when speaking with a 10-mm bite block, though the interaction between jaw positioning and lexical competition did not achieve statistical significance. Results indicate that talkers alter vowel characteristics in response both to biomechanical and linguistic demands, and that the effect of lexical characteristics is robust to the articulatory reorganization required for successful bite-block compensation.

Phonetic imitation of coarticulatory vowel nasalization.

This study investigates the spontaneous phonetic imitation of coarticulatory vowel nasalization. Speakers produced monosyllabic words with a vowel-nasal sequence either from dense or sparse phonological neighborhoods in shadowing and word-naming tasks. During shadowing, they were exposed to target words that were modified to have either an artificially increased or decreased degree of coarticulatory vowel nasality. Increased nasality, which is communicatively more facilitative in that it provides robust predictive information about the upcoming nasal segment, was imitated more strongly during shadowing than decreased nasality. An effect of neighborhood density was also observed only in the increased nasality condition, where high neighborhood density words were imitated more robustly in early shadowing repetition. An effect of exposure to decreased nasality was observed during post-shadowing word-naming only. The observed imitation of coarticulatory nasality provides evidence that speakers and listeners are sensitive to the details of coarticulatory realization, and that imitation need not be mediated by abstract phonological representations. Neither a communicative account nor a representational account could single-handedly predict these observed patterns of imitation. As such, it is argued that these findings support both communicative and representational accounts of phonetic imitation.

False memories for varying and non-varying words in American English

ABSTRACTCertain types of variation are licenced by phonotactics. For example, the American English phoneme /t/ varies word-finally (ba[t] ∼ ba[ʔ]), but not word-initially. We used a Deese–Roediger–McDermott false memory paradigm to pursue the hypothesis that, given comparable information in the speech stream, varying words (such as bat) activate less strongly than non-varying words (such as tip). We presented listeners with lists of phonological neighbours, such as rat, ban, bet, etc. (neighbours of bat), and lip, tin, type, etc. (neighbours of tip), followed by recall and recognition tasks. Results showed that participants often “remembered” the unheard words bat and tip, replicating previous work indicating that activation from neighbours can produce false memories. Most importantly, false memory rates were significantly lower for bat compared to tip, suggesting that the presence of phonotactic conditions for variability affected the lexical activation of a word, compared to the absence of such conditions.

Semantic predictability mediates effects of phonetic reduction and social variation on word recognition

Phonetic reduction due to lexical frequency, phonological neighborhood density, and discourse mention, as well as speaking style and social-indexical variation can constrain listeners’ ability to identify spoken single word tokens. In phrasal contexts, however, semantic predictability facilitates word recognition. The aim of the current study was to investigate how semantic predictability influences the intelligibility of words that vary in their lexical, stylistic, and socio-indexical properties. Listeners were presented with auditory English phrases extracted from read passages and were asked to identify each phrase. Phrases were mixed with speech-shaped noise and each contained a target word of interest. Linguistic and social properties of the target words were used to predict listeners’ target word recognition accuracy. These factors included semantic predictability, lexical frequency, neighborhood density, speaking style, discourse mention within the passage, talker gender, and talker dialect. The re...

Variation in normal hearing thresholds predicts word recognition in noise

Analyses of speech identification data collected from young, normal-hearing adults often do not include measures of listeners’ hearing. Sub-clinical variation in hearing, it is assumed, will not significantly affect the identification of speech signals presented well above threshold levels. This study tested that assumption in the context of an experiment that investigated young adults’ recognition of words with few versus many phonological neighbors produced in clear and conversational speaking styles. Words were presented in speech-shaped noise at a + 5 dB SNR. A mixed effects regression analysis was performed to account for the contributions of lexical difficulty, speaking style, order of word presentation, and listeners’ hearing (as measured by pure-tone average (PTA)). This analysis showed, as expected, that correct identification was predicted by word type (easy > hard) and speaking style (clear > conversational). It also showed that identification improved over the course of the experiment. Finally...

Interactions in the neighborhood: Effects of orthographic and phonological neighbors on N400 amplitude.

The present study investigated effects of phonological and orthographic neighborhood density on event-related potentials, with an aim to better specify the factors that determine N400 amplitude in single word reading paradigms. We orthogonally manipulated the number of orthographic and phonological neighbors of words using the Levenshtein Distance metric (OLD20 and PLD20, respectively). The results showed opposite effects of phonological neighborhood density (PND) as a function of orthographic neighborhood density (OND). Larger N400 amplitudes were elicited by words with high PND compared with low PND when OND was high, and smaller N400 amplitudes were observed with high PND compared with low PND words when OND was low. We interpret these findings using the notion of cross-code consistency, according to which the compatibility of orthographic and phonological representations activated by a given word influences the process of recognizing that word. Words with similar numbers of orthographic and phonological neighbors have more consistent spellings and pronunciations across the neighborhood, and generate larger N400 amplitudes.

Syllable Frequency and Spoken Word Recognition: An Inhibitory Effect.

Research has shown that syllables play a relevant role in lexical access in Spanish, a shallow language with a transparent syllabic structure. Syllable frequency has been shown to have an inhibitory effect on visual word recognition in Spanish. However, no study has examined the syllable frequency effect on spoken word recognition. The present study tested the effect of the frequency of the first syllable on recognition of spoken Spanish words. A sample of 45 young adults (33 women, 12 men; M = 20.4, SD = 2.8; college students) performed an auditory lexical decision on 128 Spanish disyllabic words and 128 disyllabic nonwords. Words were selected so that lexical and first syllable frequency were manipulated in a within-subject 2 × 2 design, and six additional independent variables were controlled: token positional frequency of the second syllable, number of phonemes, position of lexical stress, number of phonological neighbors, number of phonological neighbors that have higher frequencies than the word, and acoustical durations measured in milliseconds. Decision latencies and error rates were submitted to linear mixed models analysis. Results showed a typical facilitatory effect of the lexical frequency and, importantly, an inhibitory effect of the first syllable frequency on reaction times and error rates.

The influence of 2-hop network density on spoken word recognition.

The influence of 2-hop density on spoken word recognition was investigated. 2-hop density measures the density of connections among the phonological neighbors (i.e., 1-hop neighbors) and phonological neighbors of those neighbors (i.e., 2-hop neighbors) of a target word. In both naming and lexical decision tasks, words with low 2-hop density were recognized more quickly than words with high 2-hop density. Because stimuli were selected such that the number of 1-hop and 2-hop neighbors were matched across both sets of words, the results suggest that spoken word recognition is influenced by the amount of connectivity among distant neighbors of the target word-a result that is not easily accommodated by current models of spoken word recognition. A diffusion of activation framework is proposed to account for the present findings.

The phonological neighbourhood effect on short-term memory for order

ABSTRACTThere is a growing body of literature that suggests that long-term memory (LTM) and short-term memory (STM) structures that were once thought to be distinct are actually co-dependent, and that LTM can aid retrieval from STM. The mechanism behind this effect is commonly argued to act on item memory but not on order memory. The aim of the current study was to examine whether LTM could exert an influence on STM for order by examining an effect attributed to LTM, the phonological neighbourhood effect, in a task that reduced the requirement to retain item information. In Experiment 1, 18 participants completed a serial reconstruction task where neighbourhood density alternated within the lists. In Experiment 2, 22 participants completed a serial reconstruction task using pure lists of dense and sparse neighbourhood words. In Experiment 3, 22 participants completed a reconstruction task with both mixed and pure lists. There was a significant effect of neighbourhood density with better recall for dense than sparse neighbourhood words in pure lists but not in mixed lists. Results suggest that LTM exerts an influence prior to that proposed by many models of memory for order.

Lexical Considerations in the Treatment of Speech Sound Disorders in Children

The interaction between lexical and phonological development has been the focus of a growing body of research. Findings suggest that phonological ability influences word learning and that certain characteristics of words influence how words are produced by children. This article summarizes research findings regarding the effects of word frequency, phonological neighborhood density (PND), and phonotactic probability (PP) on phonological development, and describes how these factors have been manipulated to influence phonological learning in the treatment of speech sound disorder in children. Clinical applications and ideas for considering lexical factors in the selection of target words for treatment are provided.

Inflected words in production: Evidence for a morphologically rich lexicon.

Current evidence suggests that there is a difference between the representations of multimorphemic words in production and perception. In perception, it is widely believed that both whole-word and root representations exist, while in production there is little evidence for whole-word representations. The present investigation demonstrates that whole-word and root frequency independently predict the duration of words suffixed with -ing, -ed, and -s, which reveals that both root and word representations play a role in the production of inflected English words. In a second line of analysis, we find that the number of inflected phonological neighbours independently predicts the duration of monomorphemic words, which extends these results and suggests that whole-word representations exist at the lexical level. Together these results suggest that both root and word representations of inflected words are stored in the lexicon and are relevant for the production of both monomorphemic and multimorphemic words.

Lexical characteristics of Spanish and English words and the development of phonological awareness skills in Spanish-speaking language-minority children

The lexical restructuring model (LRM) is a theory that attempts to explain the developmental origins of phonological awareness (PA). According to the LRM, various characteristics of words should be related to the extent to which words are segmentally represented in the lexicon. Segmental representations of words allow children to access the parts of words needed to complete PA tasks. This study examined the relations between various lexical characteristics of Spanish and English words and the PA skills of Spanish-speaking language-minority children. Participants came from two independent samples of Spanish-speaking preschool children (Sample 1 N = 553, Sample 2 N = 600). For children in both samples, only phonotactic probability was related to children’s likelihood to respond correctly to Spanish PA items. Age of acquisition and word frequency were related to children’s likelihood to respond correctly to English PA items for children in both samples. Phonological neighborhood density and phonotactic probability were also related to children’s likelihood to respond correctly to English PA items; however, these effects were sample-specific. Children’s Spanish vocabulary knowledge moderated the effects of Spanish age of acquisition and word frequency on responses to Spanish PA items. Children’s English vocabulary knowledge moderated the effects of English phonological neighborhood density and phonotactic probability on responses to English PA items. These findings have implications for the development of PA assessments to be used with language-minority children.

Dimensions of similarity in the mental lexicon

ABSTRACTDuring language production planning, multiple candidate representations are implicitly activated prior to articulation. Lexical representations that are phonologically related to the target (phonological neighbours) are known to influence phonetic properties of the target word. However, the question of which dimensions of phonological similarity contribute to such lexical-phonetic effects remains unanswered. In the present study, we reanalyse phonetic data from a previous study, examining the contrasting predictions of different definitions of phonological similarity. Our results suggest that similarity at the level of position-specific phonological segments best predicts the influence of neighbour activation on phonetic properties of initial consonants.

Phonological Neighborhood Effects in Spoken Word Perception and Production

Research on spoken word perception and production has identified two hallmarks of spoken word processing: multiple activation of representations of the sound patterns of words in memory and subsequent competition among these patterns. Evidence for this activation-competition process has come, in part, from experimental studies examining the effects of phonological neighborhoods, which are collections of similar-sounding words that are activated in memory during both perception and production. In this article, we review more than 20 years of research on phonological neighborhood effects in spoken word processing that has demonstrated that the speed and accuracy of spoken word perception and production are, in large part, a function of the density and frequency of neighborhoods of spoken words. We conclude our review with a discussion of new avenues of research—based on recent advances in network science—that hold the promise of deepening our understanding of the mental operations involved in our uniquely human capacity for communicating with the spoken word.

Many neighborhoods: Phonological and perceptual neighborhood density in lexical production and perception

Abstract We examine the relationship of lexical representations, pronunciation variation, and word recognition, by investigating effects of two lexical variables: Phonological Neighborhood Density (the number of words that can be formed by a single phoneme substitution, addition, or deletion from the target word), as well as a measure of the perceptual similarity of a target word to other words in the lexicon. We show that perceptual similarity to other words affects recognition, but not production. Phonological Neighborhood Density, on the other hand, affects both word durations and recognition accuracy (words with many neighbors shorten and are difficult recognition targets). We interpret our results as indicating that effects of Phonological Neighborhood Density on pronunciation are not generally due to perceptual similarity of the target to other words. Our results are consistent with a more general line of research demonstrating effects of ‘central’ processes on ‘peripheral’ processes such as articulation, as well as effects of modality-specific properties, such as auditory similarity and motor movements, on measures thought to tap central processes.