Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mathematical model for the vibrato

18.08.2004


As her PhD defended at the Public University of Navarre, telecommunications engineer Ixone Arroabarren has analysed the vibrato, one of the most important tools of classical singers.



The study applies both to the teaching of singing in music as well as to the medical treatment of voice pathologies. It has put forward a mathematical model for the production of the voice that can be used both in the medical study/detection of pathologies of the vocal chords and speech as well as the teaching of the art of singing. This PhD has been developed within the framework of the research project awarded by CEIN as the best Project for the Transference of Research Result.

Amongst these differences, the engineer points out, that the vibrato is an exclusively musical characteristic which is of great use to the classical singer because, on the one hand, it enables the unmasking of possible off-key notes and, on the other, it makes sure the listener does not have the sensation that they are listening to the same sound. Furthermore, the theme itself has been of great interest to many researchers in areas such as physiology and musicology.


From an acoustic perspective, the vibrato in classical singing can be defined as a regular fluctuation in the fundamental frequency of the pitch or signal, the timbre and/or the volume of a single note. Nevertheless, the origin of these variations and their relation with mechanisms of voice production are still enigmatic.

Ixone Arroabarren’s thesis studies this theme in depth with aim of carrying out a complete characterisation of the vibrato in the art of classical singing, starting from the measuring and the performance of its most relevant acoustic characteristics, and ending with an analysis of its origin and relation to the mechanisms of voice production. In brief, what we are doing is to relate what we perceive acoustically what is generated physiologically. In this way, we offer an explanation of the collateral effects which we knew were there but the exact origin of which was unknown.

To carry out this study a number of Signal Processing tools have been used - “the most suitable in each case, given that the overall study of the vibrato has implicitly involved the resolution of very different problems, from calculating the instantaneous frequency of non-stationary signals to estimating the source by means of Inverse Filtering.

As an end result of the researcher’s study, she puts forward a mathematical model of voice production that can be used both for the study and medical treatment of vocal chord and speech pathologies as well as for learning the art of singing.

This model of vibrato production has permitted relating the most important acoustic characteristics - fundamental frequency, timbre and volume, with the most relevant elements in voice production at the level of acoustics, glottal source and response of the vocal tract. In this way we have demonstrated that the features of both elements do not show substantial changes during vibrato, only the fundamental frequency of the glottal excitation varying.

All this enables two models of signal production of the vibrato to be put forward. A Non-Interactive Model of Vibrato Production, has enabled relating the most important acoustic characteristics – variations in fundamental frequency, timbre and volume, with and Response of Vocal Tract elements in voice production. With this it has been shown that variations in fundamental frequency generated in the Glottal Source are the cause of the variations in timbre and volume, dependant on both elements of voice production.

Besides, there is an Interactive Model of Vibrato Production, which enables us to state that the variations in amplitude and frequency of the harmonics of the acoustic signal can be used to obtain more information about the mechanisms of voice production. Moreover, this model admits the inclusion of additional effects, such as synchronic variations of the Response of the Vocal Tract, which may be related to similar effects identified by other authors through physiological studies.

Garazi Andonegi | alfa
Further information:
http://www.elhuyar.com

More articles from Physics and Astronomy:

nachricht Levitating objects with light
19.03.2019 | California Institute of Technology

nachricht Stellar cartography
19.03.2019 | Leibniz-Institut für Astrophysik Potsdam

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Molecular motors run in unison in a metal-organic framework

20.03.2019 | Life Sciences

Active substance from plant slows down aggressive eye cancer

20.03.2019 | Life Sciences

Novel sensor system improves reliability of high-temperature humidity measurements

20.03.2019 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>