Speech intelligibility in closed large scale environments

The recognition capacity of useful sound signal data, of information about the source, and of the space location of the source is analyzed in relation to signal and environment characteristics, including the average phoneme duration, the reverberation time constant, the signal to noise ratios and the ratio between direct and reflected energy. The characteristics of subjective test methods required for intelligibility evaluation are described. It is suggested that the larger cost of the time test is compensated by the quantity and the quality of the resultant data, and by the possibility of deriving statistical correlations of the speech intelligibility with the various parameters on which it depends.