Publications by authors named "Douglas M Schwarz"

Profile-analysis experiments measure the ability to discriminate complex sounds based on patterns, or profiles, in their amplitude spectra. Studies of profile analysis have focused on normal-hearing listeners and target frequencies near 1 kHz. To provide more insight into underlying mechanisms, we studied profile analysis over a large target frequency range (0.

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Fricatives are obstruent sound contrasts made by airflow constrictions in the vocal tract that produce turbulence across the constriction or at a site downstream from the constriction. Fricatives exhibit significant intra/intersubject and contextual variability. Yet, fricatives are perceived with high accuracy.

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Article Synopsis
  • - This study investigates how hearing loss impacts the ability to distinguish vowel formant frequencies, focusing on the neural processing of sound in healthy and hearing-impaired ears.
  • - The research measures formant-frequency discrimination limits for people with normal hearing compared to those with mild to moderate sensorineural hearing loss, using controlled sound conditions like fixed fundamental frequency and varying bandwidths.
  • - Findings reveal that sensorineural hearing loss significantly affects the discrimination of the second formant frequency (F2), with correlations noted between discrimination limits, hearing thresholds, age, and speech-in-noise scores, while the first formant frequency (F1) is less impacted.
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Objectives: The objective of our study is to understand how listeners with and without sensorineural hearing loss (SNHL) use energy and temporal envelope cues to detect tones in noise. Previous studies of low-frequency tone-in-noise detection have shown that when energy cues are made less reliable using a roving-level paradigm, thresholds of listeners with normal hearing (NH) are only slightly increased. This result is consistent with studies demonstrating the importance of temporal envelope cues for masked detection.

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Envelope fluctuations of complex sounds carry information that is -essential for many types of discrimination and for detection in noise. To study the neural representation of envelope information and mechanisms for processing of this temporal aspect of sounds, it is useful to identify an animal model that can -sensitively detect amplitude modulations (AM). Low modulation frequencies, which dominate speech sounds, are of particular interest.

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Sorting action potentials (spikes) from tetrode recordings can be time consuming, labor intensive, and inconsistent, depending on the methods used and the experience of the operator. The techniques presented here were designed to address these issues. A feature related to the slope of the spike during repolarization is computed.

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