Aníbal Ferreira

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This paper addresses the problem of automatic identification of vowels uttered in isolation by female and child speakers. In this case, the magnitude spectrum of voiced vowels is sparsely sampled since only frequencies at integer multiples of F0 are significant. This impacts negatively on the performance of vowel identification techniques that either ignore(More)
Standard conception probabilities models assume that different acts of intercourse make independent contributions to the probability of conception in viable cycles. We propose an alternative, approximate model based on the assumption that the act of intercourse closest to the time of maximum fertility is the one most likely to have caused conception. We(More)
OBJECTIVES/HYPOTHESIS The aim of this article was to describe the results of an audio-perceptual evaluation carried out by 10 judges, on a database comprising 90 voice recordings plus 10 samples repetition, with the purpose of characterizing the intra- and interrater reliability. STUDY DESIGN Exploratory, transversal. METHODS The classification of the(More)
This paper describes our method, submitted to MIREX 2008 task " Multiple Fundamental Frequency Estimation & Tracking ". This task restricted the problem of Multiple F0 Estimation and Tracking to three cases: i) Estimate active fundamental frequencies on a frame-by-frame basis; ii) Track note contours on a continuous time basis (as in audio-to-midi); iii)(More)
This paper presents a new method for multiple fundamental frequency (F0) estimation on piano recordings. We propose a framework based on a genetic algorithm in order to analyze the overlapping overtones and search for the most likely F0 combination. The search process is aided by adaptive spectral envelope modeling and dynamic noise level estimation: while(More)
OBJECTIVES/HYPOTHESIS This article aims to establish correlations between acoustic and audio-perceptual measures using the GRBAS scale with respect to four different voice analysis software programs. STUDY DESIGN Exploratory, transversal. METHODS A total of 90 voice records were collected and analyzed with the Dr. Speech (Tiger Electronics, Seattle,(More)
The accurate estimation of the frequency of sinusoids is a frequent problem in many signal processing problems including the real-time analysis of the singing voice. In this paper we rely on a single DFT magnitude spectrum in order to perform frequency estimation in a non-iterative way. Two new frequency estimation methods are derived that are matched to(More)
In this paper we describe innovative advances to the design of a new frequency-domain algorithm to glottal source estimation whose conceptual approach we have reported recently [1]. Those advances result from accurate sinusoidal/harmonic analysis and synthesis of two concomitant acoustic signals: the glottal source signal captured near the vocal folds, and(More)