Acoustics and Perception of Clear Fricatives

Everyday observation indicates that speakers can naturally and spontaneously adopt a speaking style that allows them to be understood more easily when confronted with difficult communicative situations. Previous studies have demonstrated that the resulting speaking style, known as clear speech, is more intelligible than casual, conversational speech for a variety of listener populations. However, few studies have examined the acoustic properties of clearly produced fricatives in detail. In addition, it is unknown whether clear speech improves the intelligibility of fricative consonants, or how its effects on fricative perception might differ depending on listener population. Since fricatives are the cause of a large number of recognition errors both for normal-hearing listeners in adverse conditions and for hearing-impaired listeners, it is of interest to explore these issues in detail focusing on fricatives. The current study attempts to characterize the type and magnitude of adaptations in the clear production of English fricatives and determine whether clear speech enhances fricative intelligibility for normal-hearing listeners and listeners with simulated impairment. In an acoustic experiment (Experiment I), ten female and ten male talkers produced nonsense syllables containing the fricatives /f, &thetas;, s, [special characters omitted], v, δ, z, and [y]/ in VCV contexts, in both a conversational style and a clear style that was elicited by means of simulated recognition errors in feedback received from an interactive computer program. Acoustic measurements were taken for spectral, amplitudinal, and temporal properties known to influence fricative recognition. Results illustrate that (1) there were consistent overall clear speech effects, several of which (consonant duration, spectral peak location, spectral moments) were consistent with previous findings and a few (notably consonant-to-vowel intensity ratio) which were not, (2) 'contrastive' differences related to acoustic inventory and eliciting prompts were observed in key comparisons, and (3) talkers differed widely in the types and magnitude of acoustic modifications. Two perception experiments using these same productions as stimuli (Experiments II and III) were conducted to address three major questions: (1) whether clearly produced fricatives are more intelligible than conversational fricatives, (2) what specific acoustic modifications are related to clear speech intelligibility advantages, and (3) how sloping, recruiting hearing impairment interacts with clear speech strategies. Both perception experiments used an adaptive procedure to estimate the signal to (multi-talker babble) noise ratio (SNR) threshold at which minimal pair fricative categorizations could be made with 75% accuracy. Data from fourteen normal-hearing listeners (Experiment II) and fourteen listeners with simulated sloping elevated thresholds and loudness recruitment (Experiment III) indicate that clear fricatives were more intelligible overall for both listener groups. However, for listeners with simulated hearing impairment, a reliable clear speech intelligibility advantage was not found for non-sibilant pairs. Correlation analyses comparing acoustic and perceptual style-related differences across the 20 speakers encountered in the experiments indicated that a shift of energy concentration toward higher frequency regions and greater source strength was a primary contributor to the "clear fricative effect" for normal-hearing listeners but not for listeners with simulated loss, for whom information in higher frequency regions was less audible

Acoustic and perceptual evidence of complete neutralization of word-final tonal specification in Japanese

M.A. University of Kansas, Linguistics 2002This study investigates the extent to which Japanese lexical pitch-accent distinction is neutralized in word-final position. Native speakers of Tokyo Japanese produced minimal word pairs differing in final accent status. Words were produced both in isolation and in a sentential context, where neutralization would not be expected due to following tonal specification. Examination of pitch patterns on relevant moras revealed a clear distinction between accent-opposed pairs produced in context but no such difference between items produced in isolation. Both the words produced in isolation and the words excised from sentential contexts were then presented to Japanese listeners in a lexical identification task. Participants could clearly distinguish items extracted from sentences but identified words uttered in isolation at chance level. These results suggest that phonological neutralization of final pitch accent is complete, showing no effects of underlying specification in either production or perception

Acoustic characteristics of clearly spoken English fricatives

This is the publisher's version, also available electronically from http://scitation.aip.org/content/asa/journal/jasa/125/6/10.1121/1.2990715Speakers can adopt a speaking style that allows them to be understood more easily in difficult communication situations, but few studies have examined the acoustic properties of clearly produced consonants in detail. This study attempts to characterize the adaptations in the clear production of American English fricatives in a carefully controlled range of communication situations. Ten female and ten male talkers produced fricatives in vowel-fricative-vowel contexts in both a conversational and a clear style that was elicited by means of simulated recognition errors in feedback received from an interactive computer program. Acoustic measurements were taken for spectral, amplitudinal, and temporal properties known to influence fricative recognition. Results illustrate that (1) there were consistent overall style effects, several of which (consonant duration, spectral peak frequency, and spectral moments) were consistent with previous findings and a few (notably consonant-to-vowel intensity ratio) of which were not; (2) specific acoustic modifications in clear productions of fricatives were influenced by the nature of the recognition errors that prompted the productions and were consistent with efforts to emphasize potentially misperceived contrasts both within the English fricative inventory and based on feedback from the simulated listener; and (3) talkers differed widely in the types and magnitude of all modifications

Studies on substantially increased proteins in follicular fluid of bovine ovarian follicular cysts using 2-D PAGE and MALDI-TOF MS

BACKGROUND: The objective of this study was to identify substantially increased proteins in bovine cystic follicular fluid (FF) in order to clarify the pathology and etiology of bovine ovarian follicular cysts (BOFC). METHODS: Proteins in normal and cystic FF samples were subjected to two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and were compared using silver stained gel images with PDQuest image analysis software. Peptides from these increased spots were analyzed by matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and were identified based on the NCBI database by a peptide mass fingerprinting method. RESULTS: Comparative proteomic analysis showed 8 increased protein spots present in cystic FF. MS analysis and database searching revealed that the increased proteins in cystic FF were bovine mitochondrial f1-atpase (BMFA), erythroid associated factor (EAF), methionine synthase (MeS), VEGF-receptor, glyceraldehydes 3-phosphate dehydrogenase (GAPDH), heat shock protein 70 (HSP70), β-lactoglobulin (BLG) and succinate dehydrogenase Ip subunit (SD). CONCLUSION: Our results suggest that these proteins are overexpressed in BOFC, and that they may play important roles in the pathogenesis of BOFC. Furthermore, these proteins in the FF could be useful biomarkers for BOFC

Madelung potentials and covalency effect in strained La1−x_{1-x}Srx_xMnO3_3 thin films studied by core-level photoemission spectroscopy

We have investigated the shifts of the core-level photoemission spectra of La$_{0.6}$Sr$_{0.4}$MnO$_3$ thin films grown on three kinds of substrates, SrTiO$_3$, (LaAlO$_3$)$_{0.3}$-(SrAl$_{0.5}$Ta$_{0.5}$O$_3$)$_{0.7}$, and LaAlO$_3$. The experimental shifts of the La 4d and Sr 3d core levels are almost the same as the calculation, which we attribute to the absence of covalency effects on the Madelung potentials at these atomic sites due to the nearly ionic character of these atoms. On the other hand, the experimental shifts of the O $1s$ and Mn $2p$ core levels are negligibly small, in disagreement with the calculation. We consider that this is due to the strong covalent character of the Mn-O bonds.Comment: 4 pages, 5 figure

In-situ photoemission study of Pr_{1-x}Ca_xMnO_3 epitaxial thin films with suppressed charge fluctuations

We have performed an {\it in-situ} photoemission study of Pr_{1-x}Ca_xMnO_3 (PCMO) thin films grown on LaAlO_3 (001) substrates and observed the effect of epitaxial strain on the electronic structure. We found that the chemical potential shifted monotonically with doping, unlike bulk PCMO, implying the disappearance of incommensurate charge fluctuations of bulk PCMO. In the valence-band spectra, we found a doping-induced energy shift toward the Fermi level (E_F) but there was no spectral weight transfer, which was observed in bulk PCMO. The gap at E_F was clearly seen in the experimental band dispersions determined by angle-resolved photoemission spectroscopy and could not be explained by the metallic band structure of the C-type antiferromagnetic state, probably due to localization of electrons along the ferromagnetic chain direction or due to another type of spin-orbital ordering.Comment: 5 pages, 4 figure

Application of SOM in a health evaluation system

A health evaluation system was constructed which visualizes the living habits and health state from a person's checkup list by using the feature of SOM that multi-dimensional data can be mapped onto a two-dimensional surface. Here, three examples cases are reported. A change to the health region of the map by taking medication was visualized by the SOM from the conventional numerical expression. Also, the specific sick record converges towards the sick region of the map when the disease progresses. However, it was shown and visualized for the sick record not to converge in the case of the metastasis of a cancer even if for the same examinee, the cancer has progressed. Finally, for the display of the health point mark, and the display of the sick record, the spherical surface SOM, is demonstrated to be suited in the visualization