Purpose: In this study, the authors aimed to identify speech information processed by a hearing aid (HA) that is additive to information processed by a cochlear implant (CI) as a function of signal-to-noise ratio (SNR). Method: Speech recognition was measured with CI alone, HA alone, and CI + HA. Ten participants were separated into 2 groups; good…

This dissertation proposes a dynamical computational model of the timecourse of phonological parameter setting. In the model, phonological representations embrace phonetic detail, with phonetic parameters represented as activation fields that evolve over time and determine the specific parameter settings of a planned utterance. Existing models of…

Current theoretical approaches differ in their assessment of the influences of biomechanical and perceptual factors on speech production. This dissertation investigates these influences on the relative timing of the two gestures typically involved in the production of American English laterals: tongue tip raising and tongue dorsum backing.…

The literature reports some contradictory results on the degree of phonological specificity of infants' early lexical representations in the Romance language, French, and Germanic languages. It is not clear whether these discrepancies are because of differences in method, in language characteristics, or in participants' age. In this study, we…

In foreign accent syndrome (FAS), changes in articulation and prosody cause listeners to perceive the speaker as "foreign-sounding." Fewer than 100 cases of FAS have been described in the literature; commonly associated with brain damage, only a handful of these have been analyzed with respect to acoustic measures. Acoustic and…

The relationship between speech perception and production has been debated for a long time. The Motor Theory of speech perception (Liberman et al., 1989) claims that perceiving speech is identifying the intended articulatory gestures rather than perceiving the sound patterns. It seems to suggest that speech production precedes speech perception,…

We present the outcomes of a pronunciation training program conducted in a workplace setting with second language speakers who had lived in an English-speaking environment for an average of 19 years. The research questions concerned whether improvement would occur in the learners' perception of certain segments and prosody; in the…

Research in second language speech has often focused on listeners' accent judgment and factors that affect their perception. However, the topic of listeners' application of specific sound categories in their own perceptual judgments has not been widely investigated. The current study explored how listeners from diverse language backgrounds weighed…

This dissertation investigates how knowledge of phonological generalizations influences speech perception, with a particular focus on evidence that phonological processing is autonomous from (rather than interactive with) auditory processing. A model is proposed in which auditory cue constraints and markedness constraints interact to determine a…

Previous research has argued that fundamental frequency is a critical component of phonetic accommodation. We tested this hypothesis in an auditory naming task with two conditions. Participants in an Unfiltered Condition completed an auditory naming task with a single male model talker. A second group of participants was assigned to a Filtered…

Children hear new words from many different talkers; to learn words most efficiently, they should be able to represent them independently of talker-specific pronunciation detail. However, do children know what the component sounds of words should be, and can they use that knowledge to deal with different talkers' phonetic realizations? Experiment…

Purpose: In this study, the authors examined how signal clarity interacts with the use of sentence context information in determining speech-in-noise recognition for children with cochlear implants and children with normal hearing. Method: One hundred and twenty sentences in which the final word varied in predictability (high vs. low semantic…

Audiovisual speech consists of overlapping and invariant patterns of dynamic acoustic and optic articulatory information. Research has shown that infants can perceive a variety of basic auditory-visual (A-V) relations but no studies have investigated whether and when infants begin to perceive higher order A-V relations inherent in speech. Here, we…

Listeners rapidly adjust to talkers' pronunciations, accommodating those pronunciations into the relevant phonemic category to improve subsequent perception. Previous work has suggested that such learning is restricted to pronunciations that are representative of how the speaker talks (Kraljic, Samuel, & Brennan, 2008). If an ambiguous…

The precise structure of speech sound representations is still a matter of debate. In the present neurobiological study, we compared predictions about differential sensitivity to speech contrasts between models that assume full specification of all phonological information in the mental lexicon with those assuming sparse representations (only…