In speaker identification and speaker verification, wrong classifications can result from a high similarity between speakers that is represented in the speaker models. These similarities can be explored using the application of cluster analysis.


In speaker detection, every speaker is represented as a Gaussian Mixture Model (GMM). By using a dissimilarity measure for these models (e.g. cross-entropy), cluster analysis can be applied. Hierarchical agglomerative clustering methods are able to show structures in the form of a dendrogram.


Structures in speech corpora can be visualized and can therefore be used to select groups of highly similar or dissimilar speakers. The investigation of the structures concerning the aspect of misclassification can lead to model generation improvements.


Up to now, a thorough phonetic-acoustic and phonological description of the vowels and the vowel system of Standard Austrian German has not been provided.


Approximately 11,000 vowels of three female and three male speakers of Standard Austrian German have been segmented and analyzed acoustically.


Standard Austrian German discerns 13 vowels on five constriction locations:

  • pre-palatal for the /i/ and the /y/ vowels
  • mid-palatal for the /e/ and the /ø/ vowels
  • velar for the /u/ vowels
  • upper pharyngeal for the /o/ vowels
  • lower pharyngeal for /ɑ/

Each vowel pair consists of a constricted and an unconstricted vowel. The front vowels (pre-palatal and mid-palatal) additionally distinguish rounded and unrounded vowels. The following articulatory features sufficiently discriminate all vowels:

  • [± constricted]
  • [± front]
  • [± prepalatal]
  • [± pharyngeal]
  • [± round]

Contrary to general assumptions, F1 and F2 do not sufficiently discern the vowels of Standard Austrian German; F3 is necessary as well. Discriminatory ability is maintained over all speaking styles and prosodic positions.

Project Part 02 of the special research area German in Austria. Variation - Contact - Perception funded by FWF (FWF6002) in cooperation with the University of Salzburg

Principal Investigators: Stephan Elspaß, Hannes Scheutz, Sylvia Moosmüller

Start of the project: 1st of January 2016

Project description:

The diversity and dynamics of the various dialects in Austria are the topic of this project. Based on a new survey, different research questions will be addressed in the coming years, such as: What are the differences and changes (e.g. through processes of convergence and divergence) that can be observed within and between the Austrian dialect regions? What are the alterations in dialect change between urban and rural areas? Are there noticeable generational and gender differences with regard to dialect change? What can a comprehensive comparison of ‘real-time’ and ‘apparent-time’ analyses contribute to a general theory of language change?

To answer these questions, speech samples from a total of 160 dialect speakers, balanced for age and gender, are collected and analysed within the first four years at 40 locations in Austria. Furthermore, samples from selected speakers will be recorded and valuated under laboratory conditions to determine phonetic peculiarities as precisely as possible. In the second survey phase complementary recordings are carried out at another 100 locations in Austria in order to analyse differences and changes between the dialect landscapes in more detail. State-of-the-art dialectometric methods will be used to arrive at probabilistic statements regarding dialect variation and change in Austria. The analyses will include all linguistic levels from phonetics to syntax and lexis. A documentation of these data will be carried out on the first visual and ‘talking’ dialect atlas of Austria.

Project page of the project partners in Salzburg


Vowel and consonant quantity in Southern German varieties: D - A - CH project granted by DFG, FWF, SNF

Principal investigators: Felicitas Kleber, Michael Pucher, Sylvia Moosmüller†, Stephan Schmid 

Start of the project: 1st of June 2015

Project description:


The Central Bavarian varieties, to which the Viennese varieties belong, seem to have changed diachronically. From the first phonetic descriptions (Pfalz 1913) to more current descriptions (Moosmüller & Brandstätter 2014) the diachronic change becomes visible on several levels of the varieties.

In this project we focus on the (in)stability of the timing system, or more precise, the quantity relations in Vowel + Consonant sequences and compare our results with the project partners in Zurich and Munich.


The aims of this project are two-fold. The first aim is to develop a typology of the Vowel + Consonant quantities in Southern German varieties (Bavarian (Munich + Vienna) and Alemannic (Zurich)) in C1V1C2V2 contexts (where C2 can be either fricatives or nasals or plosives) and in consonant cluster sequences with increasing initial and final consonant cluster complexity. The second aim is to investigate prosodic changes in an apparent-time study and to examine the influence of internal factors (eg. speech rate) and external factors (language attitudes) on the production of speech.


Recordings and analyses of 40 speakers of the Viennese varieties (balanced for age, gender, and educational background) will be conducted. During the recording sessions the speakers are asked to read and repeat sentences in two speech rates. Furthermore a subset of speakers is asked to participate in an articulatory recording with an electromagnetic articulograph (EMA). These recordings take place at our project partners’ laboratory in Munich.


The results will not only provide insight in the current timing system of speakers of the Viennese varieties but also enable us to draw conclusions about sound changes in progress.



This project describes vowel systems of several languages acoustically and compares them. The project's main interest is focused on languages with acoustically insufficient descriptions thus far, e.g. Albanian, Romanian, Ful, Mandinka, or Crioulo.


Selected speakers are asked to perform a reading task and to speak spontaneously. Vowels in all positions are segmented, labeled, and analyzed. Formant frequencies (F1, F2, F3) are extracted and the vowel systems are defined.

Language specificity affects not only the number of vowels and their features, but also the extent of variability and stability of certain vowels. A given vowel of language A might be quite stable, whereas the same vowel might exert high variability in language B. In the same way, vowels might be discerned differently. For example, pre-palatal /i/ and mid-palatal /e/ are discerned by F3 in Standard Austrian German (see diagram on SAG), whereas both mid-palatal /i/ and /e/ are predominantly discerned by F2 in Modern Standard Albanian (see diagram on MSA).


In forensic speaker identification, thorough descriptions of the languages in question are often needed in order to conduct a thorough comparison.

FWF DACH I 536-G20: 2011-2013
Cooperation with the Institute of Phonetics and Speech Processing, LMU Munich.

Project leader (Austria): Sylvia Moosmüller
Project leader (Germany): Jonathan Harrington


Across languages, the distinction between so-called tense and lax vowels, e.g., Miete - Mitte ("rent" - "center") or Höhle - Hölle ("cave" - "hell"), is encountered in many languages. However, many different articulatory adjustments might cause this distinction, and these are language-specific.

In the current project, we address this issue by analysing high tense and lax vowel pairs of the type bieten - bitten ("to offer" - "to request"), Hüte - Hütte ("hats" - "hut"), and Buße - Busse ("penance" - "busses") in two related language varieties: Standard Austrian German (SAG) and Standard German German (SGG). Previous studies suggest that high lax vowel pairs like bitten, Hütte, or Busse tend to approximate their respective tense cognates bieten, Hüte, and Buße.

The research questions were investigated by a) comparing the tense and lax vowel pairs in SAG and SGG, b) by investigating whether high lax vowel pairs approximate their tense cognates in SAG, c) by investigating whether the high vowel pairs in SAG are distinguished by quality, by quantity, or by quantity relations with the following consonant, and d) by investigating whether an ongoing sound change can be observed in SAG, with young SAG speakers exhibiting a higher degree to merge the vowels than old SAG speakers.

Main Results:

SGG speakers clearly distinguish the high vowel pairs by quality, whereas speaker-specific strategies can be observed in SAG, with some speakers distinguishing high tense and lay vowel pairs by quality, others merging the quality contrast, but restricting the merger to velar contexts only, and still others merging high tense and lax vowels alltogether. In case of distinction, the differences between high tense and high lax vowels are less pronounced in SAG than in SGG and still less pronounced in the speech of young SAG speakers as compared to old SAG speakers. The same result was observed for quantity distinctions: All speakers differentiate the high vowel pairs by quantity, meaning that the tense vowels of the type bieten, Hüte, and Buße are longer than their respective lax cognates. Again, the differences are most pronounced in SGG and least pronounced in the speech of the young SAG speakers, meaning that the tense vowels of the type bieten, Hüte, and Buße are truncated in the speech of young SAG speakers as compared to old SAG speakers and SGG speakers. Results on the quantity interactions of vowel + consonant sequences prove quantifying aspects in SAG. Again, some age-specific differences emerged insofar as overall, young SAG speakers have shorter durations than old SAG speakers. However, they maintain the timing relations observed for the old SAG speakers. Results on perception strongly suggest that SAG speakers make use of quantity cues in order to distinguish the vowel pairs, whereas SGG speakers rather rely on cues connected with quality. Generally, it can be concluded that quantity distinctions are more relevant in SAG than in SGG.

Project Related Publications:

Harrington, Jonathan, Hoole, Philip, & Reubold, Ulrich. (2012). A physiological analysis of high front, tense-lax vowel pairs in Standard Austrian and Standard German. Italian Journal of Linguistics, 24, 158-183.

Brandstätter, Julia & Moosmüller, Sylvia. (in print). Neutralisierung der hohen Vokale in der Wiener Standardsprache – A sound change in progress? In M. Glauninger & A. Lenz (Eds.), Standarddeutsch in Österreich – Theoretische und empirische Ansätze. Vienna: Vandenhoeck & Ruprecht.

Brandstätter, Julia, Kaseß, Christian H., & Moosmüller, Sylvia (accepted). Quality and quantity in high vowels in Standard Austrian German. In: A. Leemann, M-J. Kolly & V. Dellwo (Eds.), Trends in phonetics and phonology in German-speaking Europe. Zurich: Peter Lang.

Cunha, Conceição, Harrington, Jonathan, Moosmüller, Sylvia, & Brandstätter, Julia (accepted). The influence of consonantal context on the tense-lax contrast in two standard varieties of German. In: A. Leemann, M-J. Kolly & V. Dellwo (Eds.), Trends in phonetics and phonology in German-speaking Europe. Zurich: Peter Lang.

Moosmüller, Sylvia. (in print). Methodisches zur Bestimmung der Standardaussprache in Österreich. In: M. Glauninger & A. Lenz (Eds.), Standarddeutsch in Österreich – Theoretische und empirische Ansätze. Vienna: Vandenhoeck & Ruprecht (=Wiener Arbeiten zur Linguistik).

Moosmüller, Sylvia & Brandstätter, Julia. (in print). Phonotactic Information in the temporal organisation of Standard Austrian German and the Viennese Dialect. Language Sciences.