Noise Duration as a Cue for Distinguishing among Fricative, Affricate, and Stop Consonants

Featural approaches to second language phonetic acquisition posit that the development of new phonetic norms relies on sub-phonemic features, expressed through a constellation of articulatory gestures and their corresponding acoustic cues, which may be shared across multiple phonemes. Within featural approaches, largely supported by research in speech perception, debate remains as to the fundamental scope or ‘size’ of featural units. The current study examines potential featural relationships between voiceless and voiced stop consonants, as expressed through the voice onset time cue. Native English-speaking learners of Spanish received targeted training on Spanish voiceless stop consonant production through a visual feedback paradigm. Analysis focused on the change in voice onset time, for both voiceless (i.e. trained) and voiced (i.e. non-trained) phonemes, across the pretest, posttest, and delayed posttest. The results demonstrated a significant improvement (i.e. reduction) in voice onset time for voiceless stops, which were subject to the training paradigm. In contrast, there was no significant change in the non-trained voiced stop consonants. These results suggest a limited featural relationship, with independent voice onset time (VOT) cues for voiceless and voices phonemes. Possible underlying mechanisms that limit feature generalization in second language (L2) phonetic production, including gestural considerations and acoustic similarity, are discussed.

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Temporal Encoding of the Voice Onset Time Phonetic Parameter by Field Potentials Recorded Directly From Human Auditory Cortex

Journal of Neurophysiology ◽

10.1152/jn.1999.82.5.2346 ◽

1999 ◽

Vol 82 (5) ◽

pp. 2346-2357 ◽

Cited By ~ 120

Author(s):

Mitchell Steinschneider ◽

Igor O. Volkov ◽

M. Daniel Noh ◽

P. Charles Garell ◽

Matthew A. Howard

Keyword(s):

Auditory Cortex ◽

Voice Onset Time ◽

Onset Time ◽

Stop Consonant ◽

Superior Temporal Gyrus ◽

Response Patterns ◽

Stop Consonants ◽

Field Potentials ◽

Heschl’S Gyrus ◽

Heschl's Gyrus

Voice onset time (VOT) is an important parameter of speech that denotes the time interval between consonant onset and the onset of low-frequency periodicity generated by rhythmic vocal cord vibration. Voiced stop consonants (/b/, /g/, and /d/) in syllable initial position are characterized by short VOTs, whereas unvoiced stop consonants (/p/, /k/, and t/) contain prolonged VOTs. As the VOT is increased in incremental steps, perception rapidly changes from a voiced stop consonant to an unvoiced consonant at an interval of 20–40 ms. This abrupt change in consonant identification is an example of categorical speech perception and is a central feature of phonetic discrimination. This study tested the hypothesis that VOT is represented within auditory cortex by transient responses time-locked to consonant and voicing onset. Auditory evoked potentials (AEPs) elicited by stop consonant-vowel (CV) syllables were recorded directly from Heschl's gyrus, the planum temporale, and the superior temporal gyrus in three patients undergoing evaluation for surgical remediation of medically intractable epilepsy. Voiced CV syllables elicited a triphasic sequence of field potentials within Heschl's gyrus. AEPs evoked by unvoiced CV syllables contained additional response components time-locked to voicing onset. Syllables with a VOT of 40, 60, or 80 ms evoked components time-locked to consonant release and voicing onset. In contrast, the syllable with a VOT of 20 ms evoked a markedly diminished response to voicing onset and elicited an AEP very similar in morphology to that evoked by the syllable with a 0-ms VOT. Similar response features were observed in the AEPs evoked by click trains. In this case, there was a marked decrease in amplitude of the transient response to the second click in trains with interpulse intervals of 20–25 ms. Speech-evoked AEPs recorded from the posterior superior temporal gyrus lateral to Heschl's gyrus displayed comparable response features, whereas field potentials recorded from three locations in the planum temporale did not contain components time-locked to voicing onset. This study demonstrates that VOT at least partially is represented in primary and specific secondary auditory cortical fields by synchronized activity time-locked to consonant release and voicing onset. Furthermore, AEPs exhibit features that may facilitate categorical perception of stop consonants, and these response patterns appear to be based on temporal processing limitations within auditory cortex. Demonstrations of similar speech-evoked response patterns in animals support a role for these experimental models in clarifying selected features of speech encoding.

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Inferior colliculus contributions to phase encoding of stop consonants in an animal model

Hearing Research ◽

10.1016/j.heares.2011.09.001 ◽

2011 ◽

Vol 282 (1-2) ◽

pp. 108-118 ◽

Cited By ~ 23

Author(s):

Catherine M. Warrier ◽

Daniel A. Abrams ◽

Trent G. Nicol ◽

Nina Kraus

Keyword(s):

Animal Model ◽

Inferior Colliculus ◽

Stop Consonants ◽

Phase Encoding

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Air Pressure Responses to Sudden Vocal Tract Pressure Bleeds During Production of Stop Consonants

Journal of Speech Language and Hearing Research ◽

10.1044/1092-4388(2004/059) ◽

2004 ◽

Vol 47 (4) ◽

pp. 784-801 ◽

Cited By ~ 3

Author(s):

David J. Zajac ◽

Mark C. Weissler

Keyword(s):

Vocal Tract ◽

Linear Trend ◽

Upper Airway ◽

Air Pressure ◽

Stop Consonants ◽

Oral Pressure ◽

The Face ◽

Computer Controlled ◽

Linear Manner ◽

Respiratory Reflexes

Two studies were conducted to evaluate short-latency vocal tract air pressure responses to sudden pressure bleeds during production of voiceless bilabial stop consonants. It was hypothesized that the occurrence of respiratory reflexes would be indicated by distinct patterns of responses as a function of bleed magnitude. In Study 1, 19 adults produced syllable trains of /pʌ/ using a mouthpiece coupled to a computer-controlled perturbator. The device randomly created bleed apertures that ranged from 0 to 40 mm 2 during production of the 2nd or 4th syllable of an utterance. Although peak oral air pressure dropped in a linear manner across bleed apertures, it averaged 2 to 3 cm H 2 O at the largest bleed. While slope of oral pressure also decreased in a linear trend, duration of the oral pressure pulse remained relatively constant. The patterns suggest that respiratory reflexes, if present, have little effect on oral air pressure levels. In Study 2, both oral and subglottal air pressure responses were monitored in 2 adults while bleed apertures of 20 and 40 mm 2 were randomly created. For 1 participant, peak oral air pressure dropped across bleed apertures, as in Study 1. Subglottal air pressure and slope, however, remained relatively stable. These patterns provide some support for the occurrence of respiratory reflexes to regulate subglottal air pressure. Overall, the studies indicate that the inherent physiologic processes of the respiratory system, which may involve reflexes, and passive aeromechanical resistance of the upper airway are capable of developing oral air pressure in the face of substantial pressure bleeds. Implications for understanding speech production and the characteristics of individuals with velopharyngeal dysfunction are discussed. KEY WORDS: stop consonants, oral air pressure, subglottal air pressure, respiratory reflexes, velopharyngeal dysfunction

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Velumtätigkeit bei der Erzeugung stimmhafter und stimmloser Nasalkonsonanten im Isländischen

Nordic Journal of Linguistics ◽

10.1017/s0332586500000640 ◽

1981 ◽

Vol 4 (1) ◽

pp. 19-28 ◽

Cited By ~ 1

Author(s):

Magnús Pétursson

Keyword(s):

Temporal Patterns ◽

Stop Consonants ◽

The South ◽

Research Instrument ◽

North West ◽

South West ◽

Different Types ◽

Nasal Consonant

In modern Icelandic, spoken in the South, West, and North-West of Iceland, there is a phonemic opposition between voiced and voiceless nasals before stop consonants. For the present investigation the research instrument was the velograph. The purpose of the research was to investigate patterns of velar movement associated with each type of nasal consonants. The results show different types of velar movement organized according to two separate temporal patterns. For the voiceless nasals the movement of the velum is more rapid and begins earlier than for the voiced nasals. There are also significant differences in the nasalization of the preceding vowel according to whether the following nasal consonant is voiced or voiceless.

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