Teresa Mendes

Melody Detection in Polyphonic Musical Signals: Exploiting Perceptual Rules, Note Salience, and Melodic Smoothness

80 Computer Music Journal Melody extraction from polyphonic audio is a research area of increasing interest. It has a wide range of applications in various fields, including music information retrieval (MIR, particularly in query-by-humming, where the user hums a tune to search a database of musical audio), automatic melody transcription, performance and expressiveness analysis, extraction of melodic descriptors for music content metadata, and plagiarism detection, to name but a few. This area has become increasingly relevant in recent years, as digital music archives are continuously expanding. The current state of affairs presents new challenges to music librarians and service providers regarding the organization of large-scale music databases and the development of meaningful methods of interaction and retrieval. In this article, we address the problem of melody detection in polyphonic audio following a multistage approach, inspired by principles from perceptual theory and musical practice. Our system comprises three main modules: pitch detection, determination of musical notes (with precise temporal boundaries, pitches, and intensity levels), and identification of melodic notes. The main contribution of this article is in the last module, in which a number of rule-based systems are proposed that attempt to extract the notes that convey the main melodic line among the whole set of detected notes. The system performs satisfactorily in a small database collected by us and in the database created for the ISMIR 2004 melody extraction contest. However, the performance of the algorithm decreased in the MIREX 2005 database. Related Work

An auditory model based approach for melody detection in polyphonic musical recordings

We present a method for melody detection in polyphonic musical signals based on a model of the human auditory system. First, a set of pitch candidates is obtained for each frame, based on the output of an ear model and periodicity detection using correlograms. Trajectories of the most salient pitches are then constructed. Next, note candidates are obtained by trajectory segmentation (in terms of frequency and pitch salience variations). Too short, low-salience and harmonically-related notes are then eliminated. Finally, the melody is extracted by selecting the most important notes at each time, based on their pitch salience. We tested our method with excerpts from 12 songs encompassing several genres. In the songs where the solo stands out clearly, most of the melody notes were successfully detected. However, for songs where the melody is not that salient, the algorithm was not very accurate. Nevertheless, the followed approach seems promising.

From Pitches to Notes: Creation and Segmentation of Pitch Tracks for Melody Detection in Polyphonic Audio

Abstract Despite the importance of the note as the basic representational symbol in Western music notation, the explicit and accurate recognition of musical notes has been a difficult problem in automatic music transcription research. In fact, most approaches disregard the importance of notes as musicological units having dynamic nature. In this paper we propose a mechanism for quantizing the temporal sequences of the detected fundamental frequencies into note symbols, characterized by precise temporal boundaries and note pitches (namely, MIDI note numbers). The developed method aims to cope with typical dynamics and performing styles such as vibrato, glissando or legato.

AIDA: a methodology independent support tool for educational software authoring

Many authoring tools have been proposed in an attempt to find more effective ways to face the challenge of developing educational software. However, most of them are reported to be restrictive, since they are strongly connected to a specific educational software development methodology. The AIDA (Ambiente Integrado para o Desenvolvimento de Aplicações educacionais) authoring environment was developed at the University of Coimbra having as its main objectives the support of most of the activities involved in authoring and making educational software development easier. The AIDA system is based on a design module, i.e. a prototyping tool allowing the creation of Windows-based software, including multimedia features. The system assists evaluation activities and it caters also for support on translation and cultural adaptation, as well as on the reutilization of educational materials. The use of the AIDA environment is illustrated by three small examples using different development methodologies.

The AIDA Approach to Educational Software Portability

AbstractSeveral research and development projects have attempted to make educational software more portable. However, in most cases, packages are developed with a particular target group in mind. It is uncommon during a software package’s development for the developers to introduce characteristics that facilitate the software’s use in different settings and, eventually, in other countries. Educational software portability is usually seen as a desirable characteristic, but in many cases no special development strategies, techniques, or tools are used to achieve that characteristic. Consequently, if someone wants to use the package in situations other than those for which it was intended, he or she must go through a difficult and expensive process of adaptation and translation. In this article, motivations for portability and some limiting factors of portability are analyzed. This article also describes the approach used in the AIDA authoring environment to facilitate translation and cultural adaptation.

AIDA: An Integrated Authoring Environment for Educational Software.

This paper describes an integrated authoring environment, AIDA (Ambiente Integrado de Desenvolvimento de Aplicações educacionais). It is an open tool, giving the author a high degree of freedom both in package characteristics and design methodologies used.This environment integrates several modules. The core of the design module is a prototyping tool, allowing the creation of evolutionary prototypes. These prototypes can include several types of multimedia components and can be used as part of the final package. The AIDA environment also includes other options that support evaluation, learning materials re-use, communication between authoring team members and translation and cultural adaptation of packages to work in different environments.An experimental version of this authoring environment was implemented and the results of its evaluation are encouraging.In this paper we also present an example of a package created with the AIDA authoring environment.

Family rituals in pediatric epilepsy: Links to parental competence and adaptation.

This cross-sectional study examined the associations between family ritual meaning and 3 indicators of parental adaptation (anxious and depressive symptoms and quality of life) via 2 dimensions of parental competence—satisfaction and efficacy—in parents of children with epilepsy. Two hundred Portuguese parents of children diagnosed with epilepsy for at least 6 months completed self-report measures assessing the main study variables. Our results showed that when parents reported stronger family ritual meaning, they also reported higher levels of parental satisfaction and efficacy, which were in turn were associated with lower psychological distress (anxious and depressive symptoms) and better quality of life of parents. This pattern of results was significant regardless of the severity of children’s epilepsy, age group, and family socioeconomic level. In the context of pediatric epilepsy, empirical evidence was found for the role of family ritual meaning in being directly and indirectly associated with parents’ adaptation outcomes by higher levels of parental satisfaction and efficacy. Focusing intervention targets on what families naturally do and recognize as their own ritual meaning may be a favorable route to address those at risk of psychological distress and lower quality of life.

SIM-BEST: integrated tools for developing computer based educational simulation programs

Educational simulations have proved their importance in the learning process. There are mainly two approaches for building these simulations: programming languages and special purpose tools. At the University of Coimbra we are developing a set of integrated tools to assist in the construction of computer based educational simulations: SIM-BEST (SIMulation: computer Based Educational Support Tools). SIM-BEST allows development of simulation programs based on different kinds of models including combined models and reusable submodels and uses essentially direct manipulation techniques, various representation, animation and interaction forms and multimedia support. It can be used individually or in a network.

Learning Foreign Languages by means of a Flexible Educational Program

ABSTRACT This paper describes the environment where a pilot-project for the introduction of computers in secondary education is taking place. The project is coordinated by the University of Coimbra and involves twelve secondary schools. In the paper is emphasized the collaboration between the Group of Informatics, some researchers from the School of Education and some teachers of the secondary schools for the development of educational software. A brief description of an educational program to aid the learning of foreign languages is presented. It is a content-free program that provides a framework into which the teacher can insert the content appropriate for his classroom situation.