THE EFFECT OF PARTIAL TIME-FREQUENCY MASKING OF THE DIRECT SOUND ON THE PERCEPTION OF REVERBERANT SPEECH

The perception of sound in real-life acoustic environments is affected by reverberation. Hence, reverberation is extensively studied in the context of auditory perception, with many studies highlighting the importance of the direct sound for perception. Based on this insight, speech processing methods often use time-frequency (TF) analysis to detect TF bins that are dominated by the direct sound, typically using the direct-to-reverberant ratio (DRR). However, the relation between the DRR in the TF bins and the spatial perception of the reverberant sound which is reproduced from these bins is still not clear. It is the aim of this paper to provide some insights into this relation. This is performed using a listening experiment, where high DRR TF bins within a reverberant speech signal have been masked. The results show that the percentage of high-DRR TF bins that were masked may better indicate the quality of spatial perception, compared to the specific value of the DRR threshold. The insights from this work could be incorporated into spatial audio techniques that reproduce the direct sound of reverberant speech. This was illustrated with an implementation of directional audio coding that was studied with an additional listening experiment supporting the previously described results.