8th European Conference on Speech Communication and Technology

Geneva, Switzerland
September 1-4, 2003


Improving Speech Intelligibility by Steady-State Suppression as Pre-Processing in Small to Medium Sized Halls

Nao Hodoshima (1), Takayuki Arai (1), Tsuyoshi Inoue (1), Keisuke Kinoshita (1), Akiko Kusumoto (2)

(1) Sophia University, Japan
(2) Portland VA Medical Center, USA

One of the reasons that reverberation degrades speech intelligibility is the effect of overlap-masking, in which segments of an acoustic signal are affected by reverberation components of previous segments [Bolt et al., 1949]. To reduce the overlap-masking, Arai et al. suppressed steady-state portions having more energy, but which are less crucial for speech perception, and confirmed promising results for improving speech intelligibility [Arai et al., 2002]. Our goal is to provide a pre-processing filter for each auditorium. To explore the relationship between the effect of a pre-processing filter and reverberation conditions, we conducted a perceptual test with steady-state suppression under various reverberation conditions. The results showed that processed stimuli performed better than unprocessed ones and clear improvements were observed for reverberation conditions of 0.8 - 1.0s. We certified that steady-state suppression was an effective pre-processing method for improving speech intelligibility under reverberant conditions and proved the effect of overlap-masking.

Full Paper

Bibliographic reference.  Hodoshima, Nao / Arai, Takayuki / Inoue, Tsuyoshi / Kinoshita, Keisuke / Kusumoto, Akiko (2003): "Improving speech intelligibility by steady-state suppression as pre-processing in small to medium sized halls", In EUROSPEECH-2003, 1365-1368.