Study of the correlation between STI and subjective intelligibility test

Abstract

The speech intelligibility can be measured by subjective and objective methods. However, objective methods should have the property of being able to predict subjective response according to the test corpus, the acoustic conditions of the transmission channel and language. In this study, it has been established the correlation of STI objective method with the subjective response of a corpus made of CVC structure logatoms, built without language barriers for Spanish language, with the aim of quantifying the intelligibility of rooms designed for normal speech (i.e. classrooms). It has been determined that in poor acoustic conditions, due to a high reverberation or to high noise background, the same STI value has two different values of correlation with the subjective response, a result that gives a warning light in using STI in poor acoustic conditions and that needs further study.