Matching Items (4)

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Interactions between Pitch and Timbre Perception in Normal-hearing Listeners and Cochlear Implant Users

Description

Pitch and timbre perception are two important dimensions of auditory perception. These aspects of sound aid the understanding of our environment, and contribute to normal everyday functioning. It is therefore

Pitch and timbre perception are two important dimensions of auditory perception. These aspects of sound aid the understanding of our environment, and contribute to normal everyday functioning. It is therefore important to determine the nature of perceptual interaction between these two dimensions of sound. This study tested the interactions between pitch perception associated with the fundamental frequency (F0) and sharpness perception associated with the spectral slope of harmonic complex tones in normal hearing (NH) listeners and cochlear implant (CI) users. Pitch and sharpness ranking was measured without changes in the non-target dimension (Experiment 1), with different amounts of unrelated changes in the non-target dimension (Experiment 2), and with congruent/incongruent changes of similar perceptual salience in the non-target dimension (Experiment 3). The results showed that CI users had significantly worse pitch and sharpness ranking thresholds than NH listeners. Pitch and sharpness perception had symmetric interactions in NH listeners. However, for CI users, spectral slope changes significantly affected pitch ranking, while F0 changes had no significant effect on sharpness ranking. CI users' pitch ranking sensitivity was significantly better with congruent than with incongruent spectral slope changes. These results have important implications for CI processing strategies to better transmit pitch and timbre cues to CI users.

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Date Created
  • 2016-12

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Vowel Normalization in Dysarthria

Description

In this study, the Bark transform and Lobanov method were used to normalize vowel formants in speech produced by persons with dysarthria. The computer classification accuracy of these normalized data

In this study, the Bark transform and Lobanov method were used to normalize vowel formants in speech produced by persons with dysarthria. The computer classification accuracy of these normalized data were then compared to the results of human perceptual classification accuracy of the actual vowels. These results were then analyzed to determine if these techniques correlated with the human data.

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Date Created
  • 2013-05

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The Role of Visual Attention In Auditory Localization

Description

Hearing and vision are two senses that most individuals use on a daily basis. The simultaneous presentation of competing visual and auditory stimuli often affects our sensory perception. It is

Hearing and vision are two senses that most individuals use on a daily basis. The simultaneous presentation of competing visual and auditory stimuli often affects our sensory perception. It is often believed that vision is the more dominant sense over audition in spatial localization tasks. Recent work suggests that visual information can influence auditory localization when the sound is emanating from a physical location or from a phantom location generated through stereophony (the so-called "summing localization"). The present study investigates the role of cross-modal fusion in an auditory localization task. The focuses of the experiments are two-fold: (1) reveal the extent of fusion between auditory and visual stimuli and (2) investigate how fusion is correlated with the amount of visual bias a subject experiences. We found that fusion often occurs when light flash and "summing localization" stimuli were presented from the same hemifield. However, little correlation was observed between the magnitude of visual bias and the extent of perceived fusion between light and sound stimuli. In some cases, subjects reported distinctive locations for light and sound and still experienced visual capture.

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Created

Date Created
  • 2016-05

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Developmental acoustic analysis of the

Description

The purpose of this study was to identify acoustic markers that correlate with accurate and inaccurate /r/ production in children ages 5-8 using signal processing. In addition, the researcher aimed

The purpose of this study was to identify acoustic markers that correlate with accurate and inaccurate /r/ production in children ages 5-8 using signal processing. In addition, the researcher aimed to identify predictive acoustic markers that relate to changes in /r/ accuracy. A total of 35 children (23 accurate, 12 inaccurate, 8 longitudinal) were recorded. Computerized stimuli were presented on a PC laptop computer and the children were asked to do five tasks to elicit spontaneous and imitated /r/ production in all positions. Files were edited and analyzed using a filter bank approach centered at 40 frequencies based on the Mel-scale. T-tests were used to compare spectral energy of tokens between accurate and inaccurate groups and additional t-tests were used to compare duration of accurate and inaccurate files. Results included significant differences between the accurate and inaccurate productions of /r/, notable differences in the 24-26 mel bin range, and longer duration of inaccurate /r/ than accurate. Signal processing successfully identified acoustic features of accurate and inaccurate production of /r/ and candidate predictive markers that may be associated with acquisition of /r/.

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Created

Date Created
  • 2017