Low Neighborhood Density Research Articles

Lexical effects on talker discrimination in adult cochlear implant usersa).

The lexical and phonological content of an utterance impacts the processing of talker-specific details in normal-hearing (NH) listeners. Adult cochlear implant (CI) users demonstrate difficulties in talker discrimination, particularly for same-gender talker pairs, which may alter the reliance on lexical information in talker discrimination. The current study examined the effect of lexical content on talker discrimination in 24 adult CI users. In a remote AX talker discrimination task, word pairs-produced either by the same talker (ST) or different talkers with the same (DT-SG) or mixed genders (DT-MG)-were either lexically easy (high frequency, low neighborhood density) or lexically hard (low frequency, high neighborhood density). The task was completed in quiet and multi-talker babble (MTB). Results showed an effect of lexical difficulty on talker discrimination, for same-gender talker pairs in both quiet and MTB. CI users showed greater sensitivity in quiet as well as less response bias in both quiet and MTB for lexically easy words compared to lexically hard words. These results suggest that CI users make use of lexical content in same-gender talker discrimination, providing evidence for the contribution of linguistic information to the processing of degraded talker information by adult CI users.

Lexical effects on talker discrimination in adult cochlear implant users

The lexical and phonological content of an utterance impacts the processing of talker-specific details in normal-hearing (NH) listeners. For example, previous research has shown that NH listeners display stronger perception of talker-specific details for real words compared to nonwords, and for nonwords with high phonotactic probability compared to nonwords with low phonotactic probability. For adult cochlear implant (CI) users, limitations in the talker-specific details conveyed by their devices may alter the reliance on lexical information in talker discrimination. The current study examined the impact of lexical content on talker discrimination in adult CI users. In a same-different talker discrimination task, word pairs – produced either by the same or different talkers – were either lexically easy (high frequency, low neighborhood density) or lexically hard (low frequency, high neighborhood density). Results showed a significant interaction between lexical content and talker pair. For same-talker pairs, accuracy was higher for lexically easy words than lexically hard words. For different-talker pairs, accuracy was higher for lexically hard words than lexically easy words. Despite limitations in talker discrimination, these preliminary results suggest that adult CI users use lexical information in the processing of talker-specific details, and additionally may rely less on acoustic-phonetic details when processing is easy.

The Role of the Root in Spoken Word Recognition in Hebrew: An Auditory Gating Paradigm.

Very few studies have investigated online spoken word recognition in templatic languages. In this study, we investigated both lexical (neighborhood density and frequency) and morphological (role of root morpheme) aspects of spoken word recognition of Hebrew, a templatic language, using the traditional gating paradigm. Additionally, we compared the traditional gating paradigm with a novel, phoneme-based gating paradigm. The phoneme-based approach allows for better control of information available at each gate. We found lexical effects with high-frequency words and low neighborhood density words being recognized at earlier gates. We also found that earlier access to root-morpheme information enabled word recognition at earlier gates. Finally, we showed that both the traditional gating paradigm and gating by phoneme paradigm yielded equivalent results.

Lexical Effects on the Perceived Clarity of Noise-Vocoded Speech in Younger and Older Listeners.

When listening to degraded speech, such as speech delivered by a cochlear implant (CI), listeners make use of top-down linguistic knowledge to facilitate speech recognition. Lexical knowledge supports speech recognition and enhances the perceived clarity of speech. Yet, the extent to which lexical knowledge can be used to effectively compensate for degraded input may depend on the degree of degradation and the listener’s age. The current study investigated lexical effects in the compensation for speech that was degraded via noise-vocoding in younger and older listeners. In an online experiment, younger and older normal-hearing (NH) listeners rated the clarity of noise-vocoded sentences on a scale from 1 (“very unclear”) to 7 (“completely clear”). Lexical information was provided by matching text primes and the lexical content of the target utterance. Half of the sentences were preceded by a matching text prime, while half were preceded by a non-matching prime. Each sentence also consisted of three key words of high or low lexical frequency and neighborhood density. Sentences were processed to simulate CI hearing, using an eight-channel noise vocoder with varying filter slopes. Results showed that lexical information impacted the perceived clarity of noise-vocoded speech. Noise-vocoded speech was perceived as clearer when preceded by a matching prime, and when sentences included key words with high lexical frequency and low neighborhood density. However, the strength of the lexical effects depended on the level of degradation. Matching text primes had a greater impact for speech with poorer spectral resolution, but lexical content had a smaller impact for speech with poorer spectral resolution. Finally, lexical information appeared to benefit both younger and older listeners. Findings demonstrate that lexical knowledge can be employed by younger and older listeners in cognitive compensation during the processing of noise-vocoded speech. However, lexical content may not be as reliable when the signal is highly degraded. Clinical implications are that for adult CI users, lexical knowledge might be used to compensate for the degraded speech signal, regardless of age, but some CI users may be hindered by a relatively poor signal.

Experiência na criação de um dicionário bilíngue de parônimos para alunos de língua estrangeira

In this paper, we would like to present a new version of a German-Russian and Russian-German paronym dictionary. This book is a pioneering work and so far unique of its kind to serve as a reference work for foreign language learners (Russian or German as L2 language), warning them of the dangers of confusing similar sounding words in their spoken language. The previous edition (PAVLOVA; SVETOZAROVA, 2012) includes many types of paronyms which are described in the paper, but this work needs to be expanded by more keywords and paronym groups. The previous version of this Dictionary will also be extended by a few more classes of paronyms. The Dictionary is primarily aimed at two target groups consisting of foreign language (L2) learners. In this case, these are Russians who learn German and Germans who learn Russian as second language. For L2 learners, the difference between words with high and low neighborhood density is larger than for native speakers. This is proven by both the “Slips of the tongue” Corpus we created and by modern psycholinguistic studies to which we refer in this paper. This is the reason why we include more paronym pairs and groups in our Dictionary than traditional reference works of this kind do. In this paper, we describe different types of paronyms, explain our methods for the selection of keywords, and clarify the structure of our Dictionary.

Alveolar stops exhibit greater coarticulatory resistance than retroflexes and dentals in Malayalam

Tight coronal contrasts in Malayalam geminates (V1t̪:V2 vs. V1t:V2 vs. V1t:V2) are examined in an Ultrasound study of tongue contours to understand the nature of coarticulatory resistance and aggressiveness. Degree of Articulatory Constraint (DAC) predicts that articulatory complexity mitigates the nature of coarticulatory resistance (CR) cross-linguistically. Findings from our study of Ultrasound tongue contours are contrary to the predictions of the DAC, where the expectation is that the directionality of CR and aggressiveness will be Vt̪:V < Vt:V < Vt:V. We find that the order of CR is Vt:V < Vt̪:V < Vt:V. Greater variability in tongue constriction location in retroflex and dentals is found compared to alveolars. Low neighborhood density alveolars exhibit low contextual adjustments even at the constriction. This is a consequence of greater articulatory complexity. Malayalam alveolars are distributionally restrictive compared to dental and retroflex places of articulation. Alveolars in Malayalam have low neighborhood densities which may indeed govern coarticulatory resistance and aggressiveness of this place of articulation. These findings have been corroborated in an acoustic study of Malayalam stops (Dutta et al., 2019). We discuss the implications of our findings for DAC and propose that sparse lexical representation coerces coarticulatory resistance in tight coronal place contrasts.

The Relation Between Vocabulary Knowledge and Phonological Awareness in Children With Cochlear Implants.

Purpose The purpose of this study was to evaluate the relation between lexical knowledge and phonological awareness performance of children with cochlear implants. Method Thirty children with cochlear implants (aged 5-7 years), 30 children with normal hearing matched for age, and 30 children with normal hearing matched for vocabulary size participated in the study. Children completed a vocabulary knowledge measure and three phonological awareness tasks with words that had high and low neighborhood density. Results Children with cochlear implants performed more poorly than their age-matched peers and similarly to their vocabulary-matched peers on phonological awareness tasks. When performance was analyzed according to the neighborhood density of the target word, children with cochlear implants and age-matched children performed better with high-density words. Across all groups, vocabulary size correlated significantly with phonological awareness performance. Conclusion Children with cochlear implants demonstrate delays in both vocabulary knowledge and phonological awareness performance, but children with cochlear implants appear to take advantage of lexical information similarly to their age-matched peers.

Relationship Between F2 Slope and Intelligibility in Parkinson's Disease: Lexical Effects and Listening Environment.

Purpose There is a complex relationship between speech production and intelligibility of speech. The current study sought to evaluate the interaction of the factors of lexical characteristics, listening environment, and the 2nd formant transition (F2 slope) on intelligibility of speakers with Parkinson's disease (PD). Method Twelve speakers with PD and 12 healthy controls read sentences that included words with the diphthongs /aɪ/, /ɔɪ/, and /aʊ/. The F2 slope of the diphthong transition was measured and averaged across the 3 diphthongs for each speaker. Young adult listeners transcribed the sentences to assess intelligibility of words with high and low word frequency and high and low neighborhood density in quiet and noisy listening conditions. The average F2 slope and intelligibility scores were entered into regression models to examine their relationship. Results F2 slope was positively related to intelligibility in speakers with PD in both listening conditions with a stronger relationship in noise than in quiet. There was no significant relationship between F2 slope and intelligibility of healthy speakers. In the quiet condition, F2 slope was only correlated with intelligibility in less-frequent words produced by the PD group. In the noise condition, F2 slope was related to intelligibility in high- and low-frequency words and high-density words in PD. Conclusions The relationship between F2 slope and intelligibility in PD was affected by lexical factors and listening conditions. F2 slope was more strongly related to intelligibility in noise than in quiet for speakers with PD. This relationship was absent in highly frequent words presented in quiet and those with fewer lexical neighbors.

Orthographic Knowledge and Lexical Form Influence Vocabulary Learning.

Many adults struggle with second language acquisition, but learn new native-language words relatively easily. We investigated the role of sublexical native-language patterns on novel word acquisition. Twenty English monolinguals learned 48 novel written words in five repeated testing blocks. Half were orthographically wordlike (e.g., nish, high neighborhood density and high segment/bigram frequency), while half were not (e.g., gofp, low neighborhood density and low segment/bigram frequency). Participants were faster and more accurate at recognizing and producing wordlike items, indicating a native-language similarity benefit. Individual differences in memory and vocabulary size influenced learning, and error analyses indicated that participants extracted probabilistic information from the novel vocabulary. Results suggest that language learners benefit from both native-language overlap and regularities within the novel language.

The Influence of Phonotactic Probability and Neighborhood Density on Children’s Production of Newly Learned Words

ABSTRACTA word learning paradigm was used to teach children novel words that varied in phonotactic probability and neighborhood density. The effects of frequency and density on speech production were examined when phonetic forms were nonreferential (i.e., when no referent was attached) and when phonetic forms were referential (i.e., when a referent was attached through fast mapping). Two methods of analysis were included: kinematic variability of speech movement patterning and measures of segmental accuracy. Results showed that phonotactic frequency influenced the stability of movement patterning whereas neighborhood density influenced phoneme accuracy. Motor learning was observed in both nonreferential and referential novel words. Forms with low phonotactic probability and low neighborhood density showed a word learning effect when a referent was assigned during fast mapping. These results elaborate on and specify the nature of interactivity observed across lexical, phonological, and articulatory domains.

Effect of Phonotactic Probability and Neighborhood Density on Word-Learning Configuration by Preschoolers With Typical Development and Specific Language Impairment

In this study, the authors assessed the effects of phonotactic probability and neighborhood density on word-learning configuration by preschoolers with specific language impairment (SLI) and typical language development (TD). One hundred thirty-one children participated: 48 with SLI, 44 with TD matched on age and gender, and 39 with TD matched on vocabulary and gender. Referent identification and naming were assessed in a computer-based learning context. For referent identification, preschoolers with TD benefited from high phonotactic probability, and the younger group also benefited from low neighborhood density. In contrast, the SLI group benefited only from high neighborhood density. For naming, older preschoolers with TD benefited most from low-density words, younger preschoolers with TD benefited most from words with high phonotactic probability, and the SLI group showed no advantage. Phonotactic probability and neighborhood density had different effects on each group that may be related to children's ability to store well-specified word forms and to the size of their extant lexicon. The authors argue that cross-study comparisons of word learning are needed; therefore, researchers should describe word, referent, and learner characteristics and the learning context and should situate their studies in a triggering → configuration + engagement model of word learning.

Identifying Complexes from Protein Interaction Networks According to Different Types of Neighborhood Density

To facilitate the realization of biological functions, proteins are often organized into complexes. While computational techniques are used to predict these complexes, detailed understanding of their organization remains inadequate. Apart from complexes that reside in very dense regions of a protein interaction network in which most algorithms are able to identify, we observe that many other complexes, while not residing in very dense regions, reside in regions with low neighborhood density. We develop an algorithm for identifying protein complexes by considering these two types of complexes separately. We test our algorithm on a few yeast protein interaction networks, and show that our algorithm is able to identify complexes more accurately than existing algorithms. A software program NDComplex for implementing the algorithm is available at http://faculty.cse.tamu.edu/shsze/ndcomplex.

Using whole-word production measures to determine the influence of phonotactic probability and neighborhood density on bilingual speech production

Numerous lexical and sublexical factors have been reported to influence speech production in monolinguals (Storkel, 2001; Vitevitch, 2002); however, whole-word production analyses have rarely been used to measure such influences. The present study investigated the effects of phonotactic probability and neighborhood density on bilingual speech production using whole-word production measures (Ingram, 2002). Five typically developing English–Spanish bilingual children were administered a picture-naming task in English and Spanish in which stimuli varied in sublexical and lexical parameters. Their English and Spanish productions were compared with those of five age-matched monolingual English- and Spanish-speaking children, respectively. No differences were found between bilinguals and monolinguals in the respective languages; however, bilinguals evidenced greater phonological complexity in Spanish than English on words with low phonotactic probability and low neighborhood density. Whole-word approximation remained similar between languages. Findings are interpreted in the context of crosslinguistic influences of sublexical and lexical factors on speech production.

For Preschoolers, Lexical Access is Purely Lexical: Neighborhood Density Effects in Child Speech Perception and the Emergent Phoneme Hypothesis

Both infants and adults are sensitive to phonotactic probability, the statistical distribution of sequences of sound below the level of the whole word. A now classic study by Jusczyk, Luce, and Charles-Luce (1994) demonstrated that 9-month-olds (but not 6-month-olds) prefer to listen to sounds patterns that occur more frequently in their native language, suggesting that sensitivity to sublexical sound patterns develops rather rapidly during the second half of the first year of life. At the other end of the spectrum, work with adults has shown that adults process speech at both the sublexical and whole-word levels. Vitevitch and Luce (1998, 1999) presented adult speakers of American English with both words and nonwords of either high or low phonotactic probability/neighborhood density (these factors were always correlated, such that no stimuli had high phonotactic probability but low neighborhood density, or vice versa). In several different perceptually-oriented tasks, adults were found to process words from dense lexical neighborhoods more slowly than words from sparse lexical neighborhoods, while nonwords with high phonotactic probability were processed more quickly than nonwords with low phonotactic probability. Vitevitch and Luce argued that the frequency of sound patterns in the stimuli was either inhibitive or facilitatory depending on whether adults were processing at the lexical or sublexical level. Real words with frequent sound patterns were responded to more slowly due to a lexical competition effect, while nonwords with frequent sound patterns were responded to more quickly due to a phonotactic facilitation effect. Lexical competition and phonotactic facilitation were argued to be operative forces at all times, with the “winning” level of processing driving the response time; in essence, if stimuli were processed more quickly as words, a lexical competition effect was observed, whereas if they were processed more quickly via their component sounds, a phonotactic facilitation effect emerged. The picture is less clear regarding the effects of phonotactic probability on speech processing in