How much to Dereverberate? Low-Latency Single-Channel Speech Enhancement in Distant Microphone Scenarios

TL;DR

This paper demonstrates the feasibility of real-time low-latency single-channel dereverberation in distant microphone scenarios, emphasizing the importance of room characteristics and early reflections for improved speech quality.

Contribution

It explores dereverberation in large, reverberant spaces at greater distances, highlighting the relationship between room parameters and dereverberation effectiveness.

Findings

Single-channel dereverberation is feasible in distant microphone scenarios.

Room volume and reverberation time significantly affect dereverberation performance.

Preserving early reflections enhances speech quality in dereverberation.

Abstract

Dereverberation is an important sub-task of Speech Enhancement (SE) to improve the signal's intelligibility and quality. However, it remains challenging because the reverberation is highly correlated with the signal. Furthermore, the single-channel SE literature has predominantly focused on rooms with short reverb times (typically under 1 second), smaller rooms (under volumes of 1000 cubic meters) and relatively short distances (up to 2 meters). In this paper, we explore real-time low-latency single-channel SE under distant microphone scenarios, such as 5 to 10 meters, and focus on conference rooms and theatres, with larger room dimensions and reverberation times. Such a setup is useful for applications such as lecture demonstrations, drama, and to enhance stage acoustics. First, we show that single-channel SE in such challenging scenarios is feasible. Second, we investigate the relationship between room volume and reverberation time, and demonstrate its importance when randomly simulating room impulse responses. Lastly, we show that for dereverberation with short decay times, preserving early reflections before decaying the transfer function of the room improves overall signal quality.