Arnaldo Candido Junior

Dr. Arnaldo Candido Junior


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
21 November 2022 in Language Resources and Evaluation
Verified
Journal Article
Open access
PDF file
AJArnaldo Candido Junior
Arnaldo Candido Junior
ECEdresson Casanova
Edresson Casanova
ASAnderson Soares
Anderson Soares
FOFrederico Santos de Oliveira
Frederico Santos de Oliveira
LOLucas Oliveira
Lucas Oliveira
SASandra Maria Aluísio
Sandra Maria Aluísio
Automatic Speech recognition (ASR) is a complex and challenging task. In recent years, there have been significant advances in the area. In particular, for the Brazilian Portuguese (BP) language, there were around 376 h publicly available for the ASR task until the second half of 2020. With the release of new datasets in early 2021, this number increased to 574 h. The existing resources, however, are composed of audios containing only read and prepared speech. There is a lack of datasets including spontaneous speech, which are essential in several ASR applications. This paper presents CORAA (Corpus of Annotated Audios) ASR with 290 h, a publicly available dataset for ASR in BP containing validated pairs of audio-transcription. CORAA ASR also contains European Portuguese audios (4.6 h). We also present a public ASR model based on Wav2Vec 2.0 XLSR-53, fine-tuned over CORAA ASR. Our model achieved a Word Error Rate (WER) of 24.18% on CORAA ASR test set and 20.08% on Common Voice test set. When measuring the Character Error Rate (CER), we obtained 11.02% and 6.34% for CORAA ASR and Common Voice, respectively. CORAA ASR corpora were assembled to both improve ASR models in BP with phenomena from spontaneous speech and motivate young researchers to start their studies on ASR for Portuguese. All the corpora are publicly available at https://github.com/nilc-nlp/CORAA under the CC BY-NC-ND 4.0 license.

12 January 2022 in Language Resources and Evaluation
Verified
Journal Article
Open access
PDF file
ECEdresson Casanova
Edresson Casanova
AJArnaldo Candido Junior
Arnaldo Candido Junior
CSChristopher Shulby
Christopher Shulby
FOFrederico Santos de Oliveira
Frederico Santos de Oliveira
João Paulo TeixeiraJoão Paulo Teixeira
João Paulo Teixeira
SASandra Maria Aluísio
Sandra Maria Aluísio
Speech provides a natural way for human–computer interaction. In particular, speech synthesis systems are popular in different applications, such as personal assistants, GPS applications, screen readers and accessibility tools. However, not all languages are on the same level when in terms of resources and systems for speech synthesis. This work consists of creating publicly available resources for Brazilian Portuguese in the form of a novel dataset along with deep learning models for end-to-end speech synthesis. Such dataset has 10.5 h from a single speaker, from which a Tacotron 2 model with the RTISI-LA vocoder presented the best performance, achieving a 4.03 MOS value. The obtained results are comparable to related works covering English language and the state-of-the-art in European Portuguese.

16 March 2022
Verified
Book Chapter
Closed access
PDF file
LGLucas Rafael Stefanel Gris
Lucas Rafael Stefanel Gris
ECEdresson Casanova
Edresson Casanova
FOFrederico Santos de Oliveira
Frederico Santos de Oliveira
ASAnderson da Silva Soares
Anderson da Silva Soares
AJArnaldo Candido Junior
Arnaldo Candido Junior

23 August 2023
Verified
Book Chapter
Closed access
PDF file
FOFrederico S. Oliveira
Frederico S. Oliveira
ECEdresson Casanova
Edresson Casanova
AJArnaldo Candido Junior
Arnaldo Candido Junior
ASAnderson S. Soares
Anderson S. Soares
AFArlindo Rodrigues Galvão Filho
Arlindo Rodrigues Galvão Filho

11 February 2023 in Applied Sciences
Verified
Journal Article
Open access
PDF file
JFJoana Filipa Teixeira Fernandes
Joana Filipa Teixeira Fernandes
DFDiamantino Freitas
Diamantino Freitas
AJArnaldo Candido Junior
Arnaldo Candido Junior
João Paulo TeixeiraJoão Paulo Teixeira
João Paulo Teixeira
The harmonic parameters Autocorrelation, Harmonic to Noise Ratio (HNR), and Noise to Harmonic Ratio are related to vocal quality, providing alternative measures of the harmonic energy of a speech signal. They will be used as input resources for an intelligent medical decision support system for the diagnosis of speech pathology. An efficient algorithm is important when implementing it on low-power devices. This article presents an algorithm that determines these parameters by optimizing the window type and length. The method used comparatively analyzes the values of the algorithm, with different combinations of window and size and a reference value. Hamming, Hanning, and Blackman windows with lengths of 3, 6, 12, and 24 glottal cycles and various sampling frequencies were investigated. As a result, we present an efficient algorithm that determines the parameters using the Hanning window with a length of six glottal cycles. The mean difference of Autocorrelation is less than 0.004, and that of HNR is less than 0.42 dB. In conclusion, this algorithm allows extraction of the parameters close to the reference values. In Autocorrelation, there are no significant effects of sampling frequency. However, it should be used cautiously for HNR with lower sampling rates.

23 August 2023
Verified
Book Chapter
Closed access
PDF file
FOFrederico S. Oliveira
Frederico S. Oliveira
ECEdresson Casanova
Edresson Casanova
AJArnaldo Candido Junior
Arnaldo Candido Junior
LGLucas R. S. Gris
Lucas R. S. Gris
ASAnderson S. Soares
Anderson S. Soares
AFArlindo Rodrigues Galvão Filho
Arlindo Rodrigues Galvão Filho