Speech recognition in classroom noise of children from 4th grade of elementary school / Reconhecimento da fala de crianças da 4 série na presença do ruído da sala de aula

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Learning process needs some optimal conditions in order to happen one of them is an adequate signal-to-noise ratio Voices teacher and background noise may be considerate when studying the influence of background noise on speech intelligibility of students at classroom In order to answer these questions this research has as goal to analyze the speech recognition-in-classroom noise for children from the 4th grade of elementary school Method this study was made in two steps: 1st measurement of background noise of a classroom of a public school located in São Paulo city downtown This acoustic measurement was executed through a partnership with INMETRO In order to set the signal-to-noise ratio of that classroom INMETRO measured the background noise level and the intensity of teachers voice 2nd measurement of speech recognition in signal to noise ratio of classroom of 35 students All of them were inscribed at the 4th Grade from elementary school All of them were asked to write the words that were presented by an artificial speaker in two different conditions: signal-to-classroom noise condition (+16,5dB(A)) and with an increase of 5 dB on signal (+21,5dB(A)) The lists were digitally recorded and were composed by 20 monosyllabic words in male voice Results - the measured background noise level varied among 53,5 to 54,1 dB(A) Leq(max) of 65,4 dB (A) The teachers voice level was at 70dB(A) The resulting signal-to classroom noise was +16,5 dB(A) For this S/N ratio the median correct speech recognition score was 76,3% for the S/N ratio of +21,5dB(A) was 91,7% It was possible to establish that for the list 1 children produced correctly 83,1% of all the presented phonemes with 3,9% of omissions and 13% of substitutions of a total of 768 phoneme occurrences For the 2nd List children produced correctly 94,8% omitted 1,1% and substituted 4,1% of a total of 805 phoneme presentations Analyzing the substitutions we found that most of all the replacements were from a low frequency phoneme for a high frequency phoneme and a from a weakest phoneme for a strong one After this study we concluded that background noise surely compromise the students speech recognition at classroom as this noise masks some of the acoustic features of teachers speech and this may interfere on childrens learning

ASSUNTO(S)

noise and children percepção da fala noise in school fonoaudiologia ruído na escola noise percepção de fala em presença de ruído crianças speech recognition in noise. aprendizagem escolas - ruído speech recognition ruído

ACESSO AO ARTIGO

Documentos Relacionados