A study on the effect by adding reverberation to speech-like masking sound

Abstract

Problems arising from the acoustical privacy point of view in public spaces have been known to be an issue. The lack of acoustical privacy has been known to affect the human's health both physically and psychologically, thus keeping the acoustical privacy in public spaces will significantly reduce social loss. Masking is the most commonly practically used technique to make a target speech unintelligible to the unintended listeners without needing to install any physical structures. Time-reversed speech has been known to effectively mask information for speech privacy applications; however, the annoyance and distraction caused by the time-reversed speech is known to be higher than other masking sound. This study explores a solution to compromise the suggested problem by adding a reverberant effect to a time-reversed speech. Subjective listening tests have been conducted to measure the intelligibility of target speech, annoyance and distraction caused by the masking sound. The experimental results suggest that adding artificial reverberation to a time-reversed speech has a significant effect to reduce the annoyance level while maintaining the masking effectiveness of the original time-reversed speech. A trend was also observed that the addition of artificial reverberation could reduce the level of distraction caused by the masking sound.