Joint effect of noise, personality and environmental factors on the intelligibility of speech

Abstract

The performance of students in speech intelligibility tests is influenced by individual characteristics such as sex and age, personality factors such as neuroticism (N), extraversion, attention and sensitivity to noise, and environmental conditions such as the location of the scholars in the classroom (LI), the location of the classroom itself with regard to extraneous noise (LO) and background noise (BN). The first aim of this study was to analyse the role of these factors in predicting performance. From a mathematical point of view the problem was to establish a model to reflect accurately the relationship between the expected proportion of successes and a set of covariates. We used a logistic regression model mainly because of its high mathematical flexibility. A further aim was to study in depth methodological questions such as the choice and assessment of the model, including its extension to a random-effects model. One hundred and seventy students participated in the study. The results indicate that only four of the factors studied had any significant bearing upon their performance: N, LI, BN and LO, and that the effect of the classroom on performance was a random one. The covariate pattern corresponding to the best performance is given by the following levels : (N) high, (LI) front row, (LO) playground and (BN) normal. For this pattern the estimated proportion of successes is 0.66