Promotion projects

Luca Jost

An established goal of research in the field of violin making acoustics is the statistical linking of experimentally obtained measurement data with the subjective evaluation of violins by test subjects. A main method is far-field measurement, which provides a frequency response of the instrument. From this measurement, acoustic characteristics can be obtained and correlated with test subjects' judgments from perception tests. The goal here is to identify the acoustic characteristics that distinguish good from bad violins. Another previously less explored approach is to correlate the structural parameters of instruments with the same acoustic characteristics. By combining both steps, it would be possible to give directly applicable recommendations for the construction of violins with a specific tonal goal.In a previous work, such relationships were identified for a data set and will be examined in the thesis in the form of case tests. Specifically, the connection between some vibration properties of the violin back and the radiation of the cavity resonance A0 was observed. The latter has emerged in the literature as the most robust quality feature of violins and is associated with the English term "richness" and preference judgments. Practical approaches that enable control of this acoustic characteristic would therefore be of direct relevance for research and, above all, for individual violin makers.The drop tests are carried out in two steps, a preliminary study in which two instruments are modified in a suitable way to enable initial insights into the acoustic behavior. Based on this, six instruments are then manufactured from the same wood using CNC technology so that, as far as possible, they only differ in the crucial parameters. These six instruments can then be used to carry out perception tests in the form of listening and playing tests in order to establish the connection between human sound judgments and the radiation of cavity resonance and thus with the structural parameters.

Kazim Cevik

Cultural and historical research on the Saz, a traditional Turkish instrument, began with the founding of the Turkish Republic at the beginning of the 20th century. Research into the acoustic properties of the Saz, however, is much more recent.The Saz is played in Anatolia and many neighboring countries of Turkey and is known by different names such as Bozuk in Syria, Bağlama in Greece or Setar or Tembur in Iran. Due to the widespread use of the instrument, not only the names but also the shapes and playing styles differ from one another. In the planned doctoral project, the term Saz will be chosen, following the choice of term used by the Turkish ethnomusicologist Mahmut Ragip Gazimihal (1900–1961).The scope of application of the Saz has developed significantly in the cities. Composers create or compose solo pieces for Saz, which shows that Saz has become established among the entire population in modern Turkey. The use of the Saz has increased in modern times, and this is particularly evident among the younger generation. The relationship and communication between the player and the instrument maker has developed positively through their shared affection for the Saz, e.g. B. when it comes to changing the scale length, string height and the number of strings.Looking back, it can be seen that Saz has developed the most in Turkey compared to other countries and is still developing today. However, the process of this development has not yet been adequately documented, neither from an ethnomusicological nor from an acoustic measurement perspective.The central concern of the work is therefore to reclassify the Saz as an instrument and to investigate the questions of whether standardization of the tuning - also with regard to practical playing aspects - is necessary and what reasons can be given for the popularity of the instrument to this day.To achieve this, the following steps should be pursued in the planned doctoral project: The comprehensive research into Saz gives you the opportunity to select the appropriate building material. In addition, the construction of the Saz can be carried out using acoustic and measurement technology with scientific standards. Using these methods, you can create a new level of sound, visualize it and analyze previously inaudible areas. Vibroacoustic and psychoacoustic investigations at the Saz are carried out in parallel in order to gain useful insights.In this work, different sazs are examined and compared with each other from an ethnomusicological as well as from an acoustic, instrumental and structural perspective. In this way, answers to questions about the ideal string height, scale and proportion are to be found and the differences in sound between traditional and modern construction methods are to be shown.