Study on method for protecting speech privacy using speech transmission index

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K12458
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Perceptual information processing
• Research Institution: Japan Advanced Institute of Science and Technology
• Principal Investigator: UNOKI MASASHI 北陸先端科学技術大学院大学, 先端科学技術研究科, 教授 (00343187)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 音声プライバシー保護 / 音声伝送指標 / 変調伝達関数 / 残響 / 聴き取りにくさ

Outline of Final Research Achievements

Protecting speech privacy is an important challenge in room acoustics. However, protecting people’s conversation from being overheard by an unintended listener, that is, making them not understandable, is difficult. This research study a method for protecting speech privacy by actively controlling the speech transmission index (STI). In this method, the STI in the simulated room can be controlled by manipulating the parameters of the simulated room impulse response (RIR). We can control the STI by convolving speech with the simulated RIR. Word intelligibility and listening difficulty tests were conducted to compare the proposed method with two conventional methods. The results showed that speech privacy can be protected by controlling STI derived by manipulating the simulated RIR. The results also showed that the proposed method can protect the privacy of conversations as effectively as those other methods can by using lower noise levels and shorter reverberation.

Free Research Field

音声信号処理