Comparing timbre estimation using auditory models with and without hearing loss

We propose a concept for evaluating signal transformations for music signals with respect to an individual hearing deficit by using an auditory model. This deficit is simulated in the model by changing specific model parameters. Our idea is extracting the musical attributes rhythm, pitch, loudness and timbre and comparing the modified model output to the original one. While rhythm, pitch, and loudness estimation are studied in previous works the focus in this paper concentrates on timbre estimation. Results are shown for the original auditory model and three models, each simulating a specific hearing loss

Time efficient optimization of instance based problems with application to tone onset detection

A time efficient optimization technique for instance based problems is proposed, where for each parameter setting the target function has to be evaluated on a large set of problem instances. Computational time is reduced by beginning with a performance estimation based on the evaluation of a representative subset of instances. Subsequently, only promising settings are evaluated on the whole data set. As application a comprehensive music onset detection algorithm is introduced where several numerical and categorical algorithm parameters are optimized simultaneously. Here, problem instances are music pieces of a data base. Sequential model based optimization is an appropriate technique to solve this optimization problem. The proposed optimization strategy is compared to the usual model based approach with respect to the goodness measure for tone onset detection. The performance of the proposed method appears to be competitive with the usual one while saving more than 84% of instance evaluation time on average. One other aspect is a comparison of two strategies for handling categorical parameters in Kriging based optimization

Musikklassifikation mittels auditorischer Modelle zur Optimierung von Hörgeräten

In der Dissertation werden für drei Musikklassifikationsprobleme - Toneinsatzzeiterkennung, Tonhöhenschätzung und Instrumentenklassifikation - Verfahren entwickelt, die auf der Ausgabe eines Simulationsmodells des menschlichen Hörvorgangs (Ohrmodell) aufbauen. Für modifizierte Ohrmodelle, die eine Hörschädigung simulieren, kann mit Hilfe dieser Verfahren evaluiert werden, wie gut Musik differenziert wird. Ziel eines Hörgeräts ist es, die Identifizierbarkeit von Musikeigenschaften zu steigern. Durch die Verknüpfung eines Hörgerätealgorithmus mit dem Ohrmodell und den Musikklassifikationsverfahren kann somit die Güte des Hörgeräts für eine durch das Ohrmodell gegebene Hörschädigung bewertet werden. Für die Paramateroptimierung des Hörgerätealgorithmus mit Hilfe der sequentiellen modellbasierten Optimierung (MBO) wird diese Bewertung als Kostenfunktion verwendet. Für die Schätzung der drei untersuchten Klassifikationsprobleme existieren bereits umfangreiche Forschungsarbeiten, die jedoch üblicherweise nicht die Ohrmodellausgabe sondern die akustische Wellenform als Grundlage nutzen. Daher werden zunächst die entwickelten Verfahren gegen diese Standardverfahren getestet. Für die Vergleichsexperimente wird ein statistischer Versuchsplan, dem ein Plackett-Burman-Design zu Grunde liegt, aufgestellt, um die untersuchten Musikdaten in einer strukturierten Form auszuwählen. Es wird gezeigt, dass die Ohrmodellbasierte Merkmalsgrundlage keinen Nachteil darstellt, denn für die Tonhöhenschätzung und die Instrumentenklassifikation werden sogar die Ergebnisse der Standardverfahren übertroffen. Lediglich bei der Einsatzzeiterkennung schneidet das entwickelte Verfahren etwas schlechter ab, für das jedoch weitere Verbessserungsideen vorgeschlagen werden. Durch den Versuchsplan werden acht musikalische Einflussgrößen berücksichtigt. Für diese wird evaluiert, wie sie sich auf die Güte der Klassifikationsverfahren auswirken. Neben vielen erwarteten Ergebnissen, z.B. die größeren Fehlerraten bei einer Streicherbegleitung auf Grund der klanglichen Nähe zum Cello, kommen auch einige unerwartete Ergebnisse heraus. Beispielsweise sind höhere Tonhöhen und kürzere Töne vorteilhaft für die Einsatzzeiterkennung, wohingegen tiefere Tonhöhen die Ergebnisse der Instrumentenerkennung verbessern. Der Versuchsplan wird auch für einen Vergleich des normalen Ohrmodells (ohne Hörschädigung) mit drei Modellen, die unterschiedliche Hörschädigungen simulieren (Hearing Dummies), verwendet. Für all diese Modelle steigen die Fehlerraten der Musikklassifikationsverfahren in plausiblen Stärken, die abhängig von den Hörschädigungen sind. Schließlich wird die praktische Anwendbarkeit des Bewertungsverfahrens in einer leicht vereinfachten Form, die aus Rechenzeitgründen lediglich die Ergebnisse der Instrumentenerkennung berücksichtigt, für die Optimierung eines Hörgerätealgorithmus getestet. Dabei wird MBO verwendet, um das Hörgerät optimal an eine starke Hörschädigung (Hearing Dummy 1) anzupassen. Durch das optimierte Hörgerät wird die Fehlklassifikationsrate stark reduziert, und auch eine vergleichende Experteneinstellung wird geschlagen (27% ohne Hörgerät, 19% mit Hörgerät und Experteneinstellung, 14% mit optimiertem Hörgerät). Wie die Auswertung des Versuchsplans zeigt, wird am stärksten die Klassifikationsgüte für Musikstücke mit Streicherbegleitung verbessert. Am Ende der Dissertation wird noch umfangreich diskutiert, welche Möglichkeiten es gibt, die Laufzeit von MBO für das vorgestellte Optimierungsproblem zu reduzieren

Efficient global optimization: Motivation, variations and applications

A popular optimization method of a black box objective function is Efficient Global Optimization (EGO), also known as Sequential Model Based Optimization, SMBO, with kriging and expected improvement. EGO is a sequential design of experiments aiming at gaining as much information as possible from as few experiments as feasible by a skillful choice of the factor settings in a sequential way. In this paper we will introduce the standard procedure and some of its variants. In particular, we will propose some new variants like regression as a modeling alternative to kriging and two simple methods for the handling of categorical variables, and we will discuss focus search for the optimization of the infill criterion. Finally, we will give relevant examples for the application of the method. Moreover, in our group, we implemented all the described methods in the publicly available R package mlrMBO

Efficient Global Optimization: Motivation, Variations, and Applications

A popular optimization method of a black box objective function is Efficient Global Optimization (EGO), also known as Sequential Model Based Optimization, SMBO, with kriging and expected improvement. EGO is a sequential design of experiments aiming at gaining as much information as possible from as few experiments as feasible by a skillful choice of the factor settings in a sequential way. In this paper we will introduce the standard procedure and some of its variants. In particular, we will propose some new variants like regression as a modeling alternative to kriging and two simple methods for the handling of categorical variables, and we will discuss focus search for the optimization of the infill criterion. Finally, we will give relevant examples for the application of the method. Moreover, in our group, we implemented all the described methods in the publicly available R package mlrMBO

The Use of Placebo and Non-Specific Therapies and Their Relation to Basic Professional Attitudes and the Use of Complementary Therapies among German Physicians - A Cross-Sectional Survey

We aimed to investigate the use of placebos ( e. g. saline injections) and non-specific treatments ( e. g. vitamin supplements in individuals without a relevant deficiency) among physicians working in private practices in Germany, and how such use is associated with the belief in and the use of complementary and alternative treatments, and basic professional attitudes. A four-page questionnaire was sent to nationwide random samples of general practitioners ( GP),internists and orthopaedists working in private practices. The response rate was 46% ( 935 of 2018). 24% of GPs, 44% of internists and 57% of orthopaedists had neither used pure placebos nor non-specific therapies in the previous 12 months. 11% percent of GPs, 12% of internists and 7% of orthopaedists had exclusively used pure placebos;30%,33% and 26%,respectively, had exclusively used non-specific therapies;35%,12% and 9% had used both. Age, sex and agreement to the statement that physicians should harness placebo effects were not significantly associated with any pattern of use. Exclusive use of pure placebos was associated with being a GP, being an internist, and having unorthodox professional views. In addition to these three factors, a lower use of CAM therapies and a wish for having more time was associated with the exclusive use of nonspecific therapies. Among physicians using both pure placebo and non-specific therapies, heterodox views were also somewhat more pronounced. However, associations were particularly strong for being a GP ( Odds ratio 11.6 ( 95%CI 6.41;21.3)) and having orthodox views ( Odds ratio 0.10 ( 95%CI 0.06;0.18)) among this group. In conclusion, the use of placebos and non-specific treatments varies strongly between medical specialties and is associated with basic professional attitudes. The findings support the view that the use of placebos and, in particular, of non-specific therapies is primarily a coping behaviour for difficult and uncertain situations

Use of Placebos and Nonspecific and Complementary Treatments by German Physicians - Rationale and Development of a Questionnaire for a Nationwide Survey

Background: We are performing a nationwide survey in a random sample ofGerman general practitioners (GPs), orthopedists, and internists on theuse of placebos and nonspecific as well as complementary treatments andtheir association with basic professional attitudes. In this article weexplain the theoretical considerations behind the study approach and thedevelopment of the questionnaire. Methods: Based on a systematic reviewof published surveys, own surveys on the topic, and on theoreticalconsiderations we developed a preliminary version of a 4-pagequestionnaire that was tested for feasibility in a convenience sample of80 participants of a general medical education event. We also performedcognitive interviews with 8 physicians to investigate whether thequestions were understood adequately. Results: The questions on typicalplacebos and complementary treatments were well understood and easy toanswer for participants. Discussions about the phrasing of questions onnonspecific treatments during interview reflected the vagueness of thisconcept; but this did not seem to create major problems when answeringthe related questions. The original questions regarding basicprofessional attitudes partly were not understood in the mannerintended. The relevant questions were modified but the interviewssuggest that these issues are difficult to grasp in a quantitativesurvey. Conclusion: Our testing procedures suggest that ourquestionnaire is well-suited to investigate our questions with somelimitations regarding the issue of basic professional attitudes