Correlation between Acoustic Analysis and Psycho-Acoustic Evaluation of Violins

This paper presents the results of an experimental study performed on seven violins obtained from a top plate made of resonance spruce and a back plate made of curly maple. Each pair of plates had a different modification to its thickness profile. Some were thickened and others were thinned compared to the classical thickness profile. Then, a soloist played a musical sequence on each violin and the acoustic signals were recorded. The sound quality of the signals was evaluated with a psycho-acoustic evaluation based on a blind questionnaire completed by listeners. It turned out that: (1) respondents with more musical experience (especially those with over 26 years of experience) were more demanding in assessing sound clarity and offered the widest range of scores in assessing this quality; (2) the musical experience of the respondents influenced to the highest degree the appreciation of the warm sound quality; (3) the scores for the violins with thinned plates were weaker, especially according to the psycho-acoustic analysis; and (4) the highest score was obtained by the violin with the thickest plates, which can be correlated with the two dominant frequencies extracted from the FFT analysis, whose values coincide with the frequencies of the B1− and B1+ modes

13. The Acoustic Analysis of Violins and the Artistic Impressions Evaluated by Musicians

Violin studies can be classified into two main types: psychoacoustic studies, which are based on the artistic perception of audibility by violinists and vibro-acoustic studies, which are based on the spectral analysis of the vibrations and sounds produced by the instruments. The paper presents the acoustic analysis of violins by means of specialized software, their main acoustic characteristics being extracted in the form of frequency spectrum, spectrograms, specific modes and number of harmonics. These results were compared with the results of the opinion poll among musicians regarding the acoustic qualities of violins, based on musical auditions. The results highlighted the fact that the acoustic analysis technique cannot detect in totality the psycho-acoustic effects of musical sounds, therefore the establishment of the acoustic quality of the instruments on objective foundations, since the personal touch of an instrumental artist aims at the approach and articulation of the musical discourse, in a complex manner, combined with the interpretation of forms and styles

Clinical research Objectives and methodology of Romanian SEPHAR II Survey. Project for comparing the prevalence and control of cardiovascular risk factors in two East-European countries: Romania and Poland

A b s t r a c t Introduction: Comparing results of representative surveys conducted in different East-European countries could contribute to a better understanding and management of cardiovascular risk factors, offering grounds for the development of health policies addressing the special needs of this high cardiovascular risk region of Europe. The aim of this paper was to describe the methodology on which the comparison between the Romanian survey SEPHAR II and the Polish survey NATPOL 2011 results is based. Material and methods: SEPHAR II, like NATPOL 2011, is a cross-sectional survey conducted on a representative sample of the adult Romanian population (18 to 80 years) and encompasses two visits with the following components: completing the study questionnaire, blood pressure and anthropometric measurements, and collection of blood and urine samples. Results: From a total of 2223 subjects found at 2860 visited addresses, 2044 subjects gave written consent but only 1975 subjects had eligible data for the analysis, accounting for a response rate of 69.06%. Additionally we excluded 11 subjects who were 80 years of age (NATPOL 2011 included adult subjects up to 79 years). Therefore, the sample size included in the statistical analysis is 1964. It has similar age groups and gender structure as the Romanian population aged 18-79 years from the last census available at the moment of conducting the survey (weight adjustments for epidemiological analyses range from 0.48 to 8.7). Conclusions: Sharing many similarities, the results of SEPHAR II and NATPOL 2011 surveys can be compared by a proper statistical method offering crucial information regarding cardiovascular risk factors in a high-cardiovascular risk European region