Christian Kaseß

  • Beschreibung

    Computermodelle für Sprachproduktion und Sprachanalyse sind sein den 1960er Jahren von wissenschaftlichen Interesse. Viele Modelle ersetzen den Vokaltrakt durch eine segementierte Röhre, wenn aber Nasale wie /n/ und /m/ oder nasaliesierte Vokale betrachtet werden sollen, sind Ein-Rohr Modelle nicht mehr ausreichend, weil durch die Nase ein zusätzlicher Resonanzkörper an den Vokaltrakt gekoppelt wird. Daher ist es notwendig, ein verzweigtes Rohrmodell zu betrachten, bei denen die Bestimmung der Querschnittsflächen aus einen vorgegebenen Sprachsignal nicht mehr trivial ist, und im Allgemeinen die Lösung eines nicht-linearen Gleichungssystems voraussetzt. 

    Das Gleichungssystem ist überbestimmt, und wir führen z.B. mittels probabilistischen Ansätzen (Bayesscher Statistik) zusätzliche Bedingungen ein, z.B. obere und untere Beschränkungen der Flächenfunktionen oder Glattheitsannahmen.

  • Introduction                                                                                                                                                   

    Rumble strips are (typically periodic) grooves place at the side of the road. When a vehicle passes over a rumble strip the noise and vibration in the car should alert the driver of the imminent danger of running off the road. Thus, rumble strips have been shown to have a positive effect on traffic safety. Unfortunately, the use of rumble strips in the close vicinity of populated areas is problematic due to the increased noise burden.

    Aims

    The aim of the project LARS (LärmArme RumpelStreifen or low noise rumble strips) was to find rumble strip designs that cause less noise in the environment without significantly affecting the alerting effect inside the vehicle. For this purpose, a number of conventional designs as well as three alternative concepts were investigated: conical grooves to guide the noise under the car, pseudo-random groove spacing to reduce tonality and thus annoyance, as well as sinusoidal depth profiles which should produce mostly vibration and only little noise and which are already used in practice.

    Methods

    Two test tracks were established covering a range of different milling patterns in order to measure the effects of rumble strips for a car and a commercial vehicle running over them. Acoustic measurements using microphones and a head-and-torso-simulator were done inside the vehicle as well as in the surroundings of the track. Furthermore, the vibration of the steering wheel and the driver seat were measured. Using the acoustics measurements, synthetic rumble strip noises were produced, in order to get a wider range of possible rumble strip designs than by pure measurements.

    Perception tests with 16 listeners were performed where the annoyance of the immissions as well as the urgency and reaction times for the sounds generated in the interior were determined also using the synthetic stimuli.

    LARS was funded by the FFG (project 840515) and the ASFINAG. The project was done in cooperation with the Research Center of Railway Engineering, Traffic Economics and Ropeways, Institute of Transportation, Vienna University of Technology, and ABF Strassensanierungs GmbH.

  • Introduction

    Railway vehicles passing through tight curves can produce a high pitched noise called curve squeal. Curve squeal is a very salient type of noise located in the high frequency range that can range between a tonal narrow band and a wide band noise. The reason for the tonal noise is lateral creepage on the top of the rail, which excites wheel vibration at frequencies corresponding to their modes. Wide band noise, however, is caused by wheel flanges touching the rail.

    Aims

    The project PAAB aims at investigating the effect on the perceived annoyance of such noises using in a perception test. Using the resulting perceptual characterization of curve squeal should aid in more adequately considering this type of noise in noise mapping.

    Methods

    Based on previous conventional large-scale emission measurements as well as new measurements at immission distances using a head-and-torso-simulator representative samples for curve squeal will be derived and used in a perception test. This will also be aided by using synthetic well defined curve squeal noise.

    PAAB is funded by the FFG (project 860523) and the Austrian Federal Railways (ÖBB). The project is done in cooperation with the Research Center of Railway Engineering, Traffic Economics and Ropeways, Institute of Transportation, Vienna University of Technololgy (project leader), Kirisits Engineering Consultants, and psiacoustic Umweltforschung und Engineering GmbH.

     

     

  • Das Projekt PASS, welches in Kooperation mit dem IEW der TU Wien und psiacoustic GmbH durchgeführt wird, beschäftigt sich mit der psychoakustischen Bewertung von Lärm. Aufbauend auf den Ergebnissen des Projektes RELSKG werden dabei hohe und niedrige Lärmschutzwände numerisch simuliert mittels der 2.5 dimensionalen Randelemente Methode (2.5 D). Der Vergleich mit Messungen zeigt, dass die Annahme einer inkohärenten Linienquelle, wie sie mit der 2.5 D Methode möglich ist, für die Reproduktion der Messergebnisse erforderlich ist. Zusätzlich werden Schienenstegdämpfer aus Messdaten psychoakustisch bewertet. Die Bewertung erfolgt in zwei Tests mit 40 Probanden. Der erste Test vergleicht die relative Lästigkeit und der zweite die Schwellen für lästiger bzw. weniger lästig. Es ergab sich, dass Güterzüge bei gleichen A-Pegel als weniger lästig als Personenzüge eingestuft werden und dass bei gleichen A-Pegel der Lärm hinter einer Lärmschutzwand als geringfügig lästiger empfunden wird. Das Projekt starte in 2013 und läuft bis Ende 2014.

  • Objective:

    Standard noise mapping software use geometrical approaches to determine insertion loss for a noise barrier. These methods are not well suited for evaluating complex geometries e.g. curved noise barriers or noise barriers with multiple refracting edges. Here, we aim at deriving frequency and source- as well as receiver-position dependent adjustments using the boundary element method. Further, the effect of absorbing layers will be investigated as a function of the geometry. Results will be incorporated into a standard noise mapping software.

    Method:

    The cross-sections of different geometries are first parameterized and discretized and then evaluated using two-dimensional boundary element simulations. The BEM code was developed at our institute. Different parameter sets are evaluated in order to derive the adjustments for the specific geometries compared to a straight noise barrier. To make the simulations more realistic, a grassland impedance model is used instead of a fully reflecting half plane. Simulations will also be evaluated using measurements from actual noise barriers.

    Wirkung einer T-Wand bei 800 Hz

    Project partners:

    • TAS Schreiner (measurements)
    • Soundplan (implementation in sound mapping software)

    Funding:

    This project is funded from the VIF2011 call of the FFG (BMVIT, ASFINAG, ÖBB)

  • 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

    Objective:

    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.