Articulation Of Nasal Consonants Research Articles

Acoustic properties for place of articulation in nasal consonants: A cross-linguistic study

Previous critical band analyses have shown distinctive energy patterns for place of articulation in nasal consonants in English [K. M. Kurowski and S. E. Blumstein, J. Acoust. Soc. Am. 81, 1917–1927 (1987)]. This study explored the extent to which these properties emerged across various languages (English, Polish, and French) by refining and evaluating a metric measuring rapid spectral changes in the vicinity of the nasal release. Utterances spoken by male and female speakers included nasals in five vowel contexts and two syllable positions. The results for syllable-initial nasals showed that the metric correctly classifies labial and coronal consonants in English (83%), Polish (87%), and French (78%). Nasals in syllable-initial clusters yielded similar results. Although some gender differences and vowel context effects were noted, the integrity of the boundaries of the broadly defined target areas of Bark 5–11 for labials and Bark 11–16 for coronals was generally maintained. The metric's overall success is viewed as support for a theory of acoustic invariance. [Work supported by NIH.]

Relational spectral features for place of articulation in nasal consonants

Much recent research on acoustic cues for consonants' places of articulation has focused upon the nature of the rapid spectral changes that take place between signal portions corresponding to consonantal closure and adjacent vowels. The study reported here builds on the foundation laid by earlier studies that have explored techniques for representing spectral change and for classifying place of articulation of nasal consonants using features extracted from rapid spectral changes that take place over murmur-to-vowel transitions. A new procedure is reported that avoids the use of predetermined absolute frequency bands in deriving parameters of spectral change in nasals. In experiments using the speech of 20 female and 20 male talkers, in a variety of physical and perceptual spectral scalings, application of the new procedure results in 77% correct classification of place of articulation of syllable-initial nasals and 51% correct classification of place of articulation of syllable-final nasals (for which there is a three-way contrast). Tested on the same data, a technique using predetermined absolute frequency bands produced 72% correct classification of syllable-initial nasals.

Across‐talker acoustic properties for place of articulation in nasal consonants

Several recent investigations of nasal consonants have focused upon the nature of the spectral change that takes place over the acoustic boundaries between nasal murmurs and vowels. Existing findings that use an algorithmic classification of place of articulation in nasals are based upon data from only a small numbers of talkers. A new method for parametrizing spectral change in nasal‐to‐vowel transitions was developed and was used to develop classification criteria that were applied to a larger talker base of 20 female and 20 male talkers who produced a total of 854 nasal‐initial tokens. Male‐female differences of a predicted kind (approximately 1 Bark spectral shift) were detected. However, the automatic classification criteria were sufficiently robust that, even ignoring such spectral shifts, the technique yielded approximately 79% correct classification of place of articulation in initial nasals. [Research supported by Alvey Project MMI 092.

Acoustic properties for place of articulation in nasal consonants.

The goal of this study was to determine whether acoustic properties could be derived for English labial and alveolar nasal consonants that remain stable across vowel contexts, speakers, and syllable positions. In experiment I, critical band analyses were conducted of five tokens each of [m] and [n] followed by the vowels [i e a o u] spoken by three speakers. Comparison of the nature of the changes in the spectral patterns from the murmur to the release showed that, for labials, there was a greater change in energy in the region of Bark 5-7 relative to that of Bark 11-14, whereas, for alveolars, there was a greater change in energy from the murmur to the release in the region of Bark 11-14 relative to that of Bark 5-7. Quantitative analyses of each token indicated that over 89% of the utterances could be appropriately classified for place of articulation by comparing the proportion of energy change in these spectral regions. In experiment II, the spectral patterns of labial and alveolar nasals produced in the context of [s] + nasal ([ m n]) + vowel ([ i e a o u]) by two speakers were explored. The same analysis procedures were used as in experiment I. Eighty-four percent of the utterances were appropriately classified, although labial consonants were less consistently classified than in experiment I. The properties associated with nasal place of articulation found in this study are discussed in relation to those associated with place of articulation in stop consonants and are considered from the viewpoint of a more general theory of acoustic invariance.

Perceptual integration of the murmur and formant transitions for place of articulation in nasal consonants.

This study reassessed the role of the nasal murmur and formant transitions as perceptual cues for place of articulation in nasal consonants across a number of vowel environments. Five types of computer-edited stimuli were generated from natural utterances consisting of [m n] followed by [i e a o u]: (1) full murmurs; (2) transitions plus vowel segments; (3) the last six pulses of the murmur; (4) the six pulses starting from the beginning of the formant transitions; and (5) the six pulses surrounding the nasal release (three pulses before and three pulses after). Results showed that the murmur provided as much information for the perception of place of articulation as did the transitions. Moreover, the highest performance scores for place of articulation were obtained in the six-pulse condition containing both murmur and transition information. The data support the view that it is the combination of nasal murmur plus formant transitions which forms an integrated property for the perception of place of articulation.