Acoustic correlates of fortis/lenis in San Francisco Ozolotepec Zapotec

Analyses of the Zapotec family of languages often divide consonants into categories of strong and weak consonants, more commonly known as fortis and lenis. These given categories usually correspond to voiceless and voiced, respectively. In San Francisco Ozolotepec Zapotec (SFOZ) and Santa Catarina Xanaguía Zapotec (SCXZ), prior analyses describe the fortis/lenis distinction in terms of duration, voicing, and articulatory force. This description parallels other impressionistic descriptions in Isthmus-Valley and Southern Zapotec variants. However, no study has objectively identified the acoustic patterns of the fortis/lenis contrast in SFOZ or in any Southern, Valley, or Isthmus Zapotec language. A previous instrumental study of the northern Zapotec variant of Yateé describes the fortis/lenis contrast in terms of duration, glottal width, and closure width. A similar experimental study of the northern variant spoken in Yalálag describes the fortis/lenis contrast in terms of duration, voice onset time (VOT) and voicing, and amplitude. Both conclusions reject the terms fortis/lenis and point to characterization of the contrast in terms of geminate/single. My intention in this thesis is to present acoustic analyses of recordings made by native Zapotec speakers of both SFOZ and SCXZ. I analyze the acoustic properties of the word-final fortis/lenis consonant contrast of SFOZ, with occasional reference to data from SCXZ. Parallel to instrumental results for Yalálag Zapotec (Avelino 2001) and Yateé Zapotec (Jaeger 1983), duration is a primary characteristic differentiating fortis and lenis consonants in SFOZ and SCXZ. Data from six adult male speakers of SFOZ reveal a second acoustic correlate of fortis and lenis segments in word-final position, quality of the preceding vowel. Voicing and VOT add to the phonetic contrast, but are not reliable cues in SFOZ. In contrast with Jaeger\u27s results, which found that fortis consonants have consistently higher ... average amplitudes than those of the lenis consonants (1983:183), I found no difference in the average amplitude of fortis/lenis sonorants. In contrast with variation in sonorants in Yalálag, SFOZ sonorants--both nasals and laterals--match the duration patterns of obstruents: fortis consonants are long and lenis consonants are short. In SCXZ, obstruents can be defined in terms of voicing; however this distinction is considerably less reliable in SFOZ

Categories, words and rules in language acquisition

Acquiring language requires learning a set of words (i.e. the lexicon) and abstract rules that combine them to form sentences (i.e. syntax). In this thesis, we show that infants acquiring their mother tongue rely on different speech categories to extract: words and to abstract regularities. We address this issue with a study that investigates how young infants use consonants and vowels, showing that certain computations are tuned to one or the other of these speech categories..

The acoustics of place of articulation in English plosives

PhD ThesisThis thesis investigates certain aspects of the acoustics of plosives’ place of articulation that have not been addressed by most previous studies, namely: 1. To test the performance of a technique for collapsing F2onset and F2mid into a single attribute, termed F2R. Results: F2R distinguishes place with effectively the same accuracy as F2onset+F2mid, being within ±1 percentage point of F2onset+F2mid at its strongest over most of the conditions examined. 2. To compare the strength of burst-based attributes at distinguishing place of articulation with and without normalization by individual speaker. Results: Lobanov normalization on average boosted the classification of individual attributes by 1.4 percentage points, but this modest improvement shrank or disappeared when the normalized attributes were combined into a single classification. 3. To examine the effect of different spectral representations (Hz-dB, Bark-phon, and Bark-sone) on the accuracy of the burst attributes. The results are mixed but mostly suggest that the choice between these representations is not a major factor in the classification accuracy of the attributes (mean difference of 1 to 1.5 percentage points); the choice of frequency region in the burst (mid versus high) is a far more important factor (13 percentage-point difference in mean classification accuracy). 4. To compare the performance of some traditional-phonetic burst attributes with the first 12 coefficients of the discrete cosine transform (DCT). The motivation for this comparison is that phonetic science has a long tradition of developing burst attributes that are tailored to the specific task of extracting place-of-articulation information from the burst, whereas automatic speech recognition (ASR) has long used attributes that are theoretically expected to capture more of the variance in the burst. Results: the DCT coefficients yielded a higher burst classification accuracy than the traditional phonetic attributes, by 3 percentage points.Economic and Social Research Counc

Emotion Recognition from Speech Signals and Perception of Music

This thesis deals with emotion recognition from speech signals. The feature extraction step shall be improved by looking at the perception of music. In music theory, different pitch intervals (consonant, dissonant) and chords are believed to invoke different feelings in listeners. The question is whether there is a similar mechanism between perception of music and perception of emotional speech. Our research will follow three stages. First, the relationship between speech and music at segmental and supra-segmental levels will be analyzed. Secondly, the encoding of emotions through music shall be investigated. In the third stage, a description of the most common features used for emotion recognition from speech will be provided. We will additionally derive new high-level musical features, which will lead us to an improvement of the recognition rate for the basic spoken emotions