Melanie Weirich

Differences in acoustic vowel space and the perception of speech tempo

Abstract Despite various studies describing longer segment durations and slower speaking rates in females than males, there appears to be a stereotype of women speaking faster than men. To investigate the mismatch between empirical evidence and this widespread stereotype, listening experiments were conducted to test whether a relationship between perceived tempo and acoustic vowel space size might exists. If a speaker traverses a larger acoustic vowel space than another speaker within the same time then this speaker might be perceived as speaking faster. To test this, two listening experiments with either exclusively female or male speakers but with varying vowel space sizes were conducted. Listeners were asked to rate the perceived speech tempo of same-sex speaker pairs. The stimuli were manipulated to have the same segment durations and f0 contour. Results indicate that a positive correlation between acoustic vowel space size and perceived speech tempo exists. Since females exhibit on average a larger acoustic vowel space than males, it is suggested that the stereotype of faster speaking women might arise from this.

Speech planning and dynamics

What do we do when we are about to utter speech? On which linguistic units do we rely? How do these units evolve from childhood to adulthood, or across time for a given language? How do we assemble these units under the influences of syntactic, phonological and prosodic rules? Do we plan the whole sequence at once? Do we plan the movements of the tongue, jaw, and lips underlying speech in the same way that we plan other movements? What tools have scientists developed to investigate these questions using observation of articulatory and acoustic signals? This book addresses these issues in eight chapters. Written by specialists in the field, these chapters provide the readers with a large overview of the literature, and illustrate the research challenges using selected examples of experimental studies.

Inter-speaker articulatory variability during vowel-consonant-vowel sequences in twins and unrelated speakers

The purpose of this study is to examine and compare the amount of inter-speaker variability in the articulation of monozygotic twin pairs (MZ), dizygotic twin pairs (DZ), and pairs of unrelated twins with the goal of examining in greater depth the influence of physiology on articulation. Physiological parameters are assumed to be very similar in MZ twin pairs in contrast to DZ twin pairs or unrelated speakers, and it is hypothesized that the speaker specific shape of articulatory looping trajectories of the tongue is at least partly dependent on biomechanical properties and the speakers individual physiology. By means of electromagnetic articulography (EMA), inter-speaker variability in the looping trajectories of the tongue back during /VCV/ sequences is analyzed. Results reveal similar looping patterns within MZ twin pairs but in DZ pairs differences in the shape of the loop, the direction of the upward and downward movement, and the amount of horizontal sliding movement at the palate are found.

Perceptual evidence for allophonic variation of the palatal fricative /ç/ in spontaneous Berlin German.

Auer (2004) postulates that the multi‐ethnolect Kiezdeutsch (Berlin, Germany) differentiates three realizations of /ɪc/: [ɪc]; [ɪ∫]; [ɪφ]. Acoustic analyzes of 1192 tokens of /c/ from the ZAS‐spontaneous speech database (collected from nine adolescent speakers of the Kiezdeutsch multi‐ethnolect as spoken in Berlin) showed no reliable differences in kurtosis, skewness, cog, or peak between items impressionistically categorized into these three groups. Further, in the spontaneous speech of middle‐aged monolingual speakers of the local Berlin dialect [∫] variants of /c/ were also detected, although here this alternation is not attested. The hypotheses are (1) that Berlin‐German also has [∫] as an allophonic variant of /c/ and (2) that Kiezdeutsch has a 3‐way‐split of this category. To evaluate the perceptual validity of these assumptions, tests are being conducted asking native Berliners to rate the category membership of excised variant realizations of /c/ and /∫/ from the Kiezdeutsch‐ and Berlin‐database o...

Acoustic vowel space size and perceived speech tempo

“Females speak faster than males.” Although several studies have proved this stereotype to be wrong [Byrd (1994)], it is still a widespread belief in many languages and within both genders. The interesting question is why. Two findings are particularly relevant regarding this stereotype: First, females reveal a greater acoustic vowel space than males [Hillenbrand et al. (1995)]. Second, a stimulus with a moving f0-contour is perceived as faster than the same stimulus with a monotonous contour [Lehiste (1976)]. From that, we might propose that if a dynamic f0 contour triggers the perception of a faster speaking rate, then a larger acoustic vowel space might have the same effect. The reason for female speakers being perceived as speaking at a faster tempo, then, is that they traverse on average a larger acoustic vowel space within the same time-frame than male speakers do. Furthermore, we could also expect a relationship between vowel space size and perceived speech tempo within the same gender. A perceptio...

Investigating the relationship between average speaker fundamental frequency and acoustic vowel space size.

The purpose of this study is to investigate the potential relationship between speaking fundamental frequency and acoustic vowel space size, thus testing a possible perceptual source of sex-specific differences in acoustic vowel space size based on the greater inter-harmonic spacing and a poorer definition of the spectral envelope of higher pitched voices. Average fundamental frequencies and acoustic vowel spaces of 56 female German speakers are analyzed. Several parameters are used to quantify the size and shape of the vowel space defined by /iː ε aː [symbol: see text] uː/ such as the area of the polygon spanned by the five vowels, the absolute difference in F1 or F2 between /iː/ and /uː/ or /aː/, and the Euclidian distance between /iː/ and /aː/. In addition, the potential impact of nasality on the vowel space size is examined. Results reveal no significant correlation between fundamental frequency and vowel space size suggesting other factors must be responsible for the larger female acoustic vowel space.

Individual differences in acoustic and articulatory undershoot in a German diphthong – Variation between male and female speakers

Abstract Individual differences in speech production and, more specifically, in the realization of stress contrasts have been found previously (e.g. de Jong, 1995 ). This study extends this line of work by investigating potential gender-specific differences in the realization of different accent conditions and more specifically in the degree of undershoot. The reason suggested for these differences is the under-exploitation of the larger male articulatory space during running speech. Differences between male and female speakers in undershoot are investigated (a) by comparing the degree of undershoot in various accent conditions between male and female diphthong productions, and (b) by analyzing the degree of undershoot in relation to a speaker’s maximum articulatory vowel space. Articulatory and acoustic data from 11 German speakers (5 males, 6 females) of the diphthong /aɪ/ were analyzed in absolute terms and after normalization for a speaker’s maximal articulatory space. In addition to speaker-specific differences in undershoot and in the acoustic-articulatory relationship, results support gender-specific differences, with males exhibiting more undershoot than females in both articulatory and acoustic terms. After normalization with respect to a speaker’s maximum articulatory vowel space, females exhibit larger tongue back trajectories than males.

Spectral moments vs discrete cosine transformation coefficients: Evaluation of acoustic measures distinguishing two merging German fricatives

The results of the quantification of the acoustic differences between German /ç/ and /ʃ/ in three speaker groups with varying contrast realizations are presented. Data for two speaker groups were collected in Berlin and Kiel, where the contrast is still realized. Data for a third group were collected in Berlin from speakers of Hood German-a youth-style multiethnolect spoken by adolescents in multilingual and multicultural neighborhoods of Berlin-where the contrast has weakened or is even lost. A forced choice perception test showed that listeners reliably differentiate these two fricatives in minimal pairs produced by the speakers from Berlin and Kiel, but fail to do so for the productions of the Hood German speakers. The acoustic analysis reveals that spectrally, the fricatives are very similar in all varieties. The spectral moments (Center of Gravity, standard deviation, kurtosis, skewness) fail to reveal the differences between the fricatives that are apparent from visual inspection of the spectra and the perceived auditory differences. Analyses of the discrete cosine transformation coefficients, however, better quantify these differences. This study suggests that minute differences between fricatives that vary between speaker groups may be captured more reliably with discrete cosine transformations compared to spectral moments.

/oy/ as an identity marker of Hood German in Berlin

A recent observation of multi-cultural urban German speech as spoken in Berlin is that the diphthong /oy/ is realized more centralized and fronted compared to the standard variety of Berlin German. For this study, spontaneous speech data was collected through standardized interviews from 11 female speakers from different neighborhoods in Berlin. Their speech was orthographically transcribed and added to a database that allows for searching for all occurrences of the diphthong in its naturally occurring context in unscripted speech. So far, 654 occurrences of these vowels have been analyzed. Measurements of the first and second formants were taken at five equally distanced points throughout the diphthong. Linear mixed effects models were run with different points across the F2-formant as the dependent variable in the two varieties of German. The second formant serves as an estimate of the degree of fronting in the two varieties of German. Results indicate that the nucleus of the /oy/ is realized more cent...