Hwan Sik Yun

Voice activity detection based on generalized gamma distribution

We propose a voice activity detection (VAD) algorithm based on the generalized gamma distribution (G/spl Gamma/D). The distributions of noise spectra and noisy speech spectra, including speech-inactive intervals, are modeled by a set of G/spl Gamma/Ds and applied to the likelihood ratio test (LRT) for VAD. The parameters of G/spl Gamma/D are estimated through an on-line maximum likelihood (ML) estimation procedure where the global speech absence probability (GSAP) is incorporated under a forgetting scheme. Experimental results show that the proposed VAD algorithm, based on G/spl Gamma/D, outperformed the algorithms based on other statistical models.

Acoustic Data Transmission Based on Modulated Complex Lapped Transform

Acoustic data transmission is a technique to embed the data in a sound wave imperceptibly and to detect it at the receiver. This letter proposes a novel acoustic data transmission system designed based on the modulated complex lapped transform (MCLT). In the proposed system, data is embedded in an audio file by modifying the phases of the original MCLT coefficients. The data can be transmitted by playing the embedded audio and extracting it from the received audio. By embedding the data in the MCLT domain, the perceived quality of the resulting audio could be kept almost similar as the original audio. The system can transmit data at several hundreds of bits per second (bps), which is sufficient to deliver some useful short messages.

Audio Fingerprinting Based on Multiple Hashing in DCT Domain

Audio fingerprinting techniques aim at successfully performing content-based audio identification even when the audio signals are slightly or seriously distorted. In this letter, we propose a novel audio fingerprinting technique based on multiple hashing. In order to improve the robustness of hashing, multiple hash strings are generated through the discrete cosine transform (DCT) which is applied to the temporal energy sequence in each subband. Experimental results show that the proposed algorithm outperforms the Philips Robust Hash (PRH) algorithm under various distortions.

Robust Data Hiding for MCLT Based Acoustic Data Transmission

Acoustic data transmission enables a short-range wireless communication between the loudspeaker and microphone. A transmitter embeds a data stream into a base audio signal such as music or commercial advertisement and broadcasts the data through the air by playing back the data-embedded sound using a loudspeaker. A receiver picks up the sound signal using microphone and extracts the hidden message. In our previous work, we proposed an acoustic data transmission system which takes advantage of the phase modification of the modulated complex lapped transform (MCLT) coefficients. In this letter, we propose several techniques to realize a more robust communication system in real noisy environment.

DCT based multiple hashing technique for robust audio fingerprinting

Audio fingerprinting techniques should successfully perform content-based audio identification even when the audio files are slightly or seriously distorted. In this paper, we present a novel audio fingerprinting technique based on combining fingerprint matching results for multiple hash tables in order to improve the robustness of hashing. Multiple hash tables are built based on the discrete cosine transform (DCT) which is applied to the time sequence of energies in each sub-band. Experimental results show that the recognition errors are significantly reduced compared with Philips Robust Hash (PRH) [1] under various distortions.

Frame Splitting Scheme for Error-Robust Audio Streaming over Packet-Switching Networks

This letter presents a novel frame splitting scheme for an error-robust audio streaming over packet-switching networks. In our approach to perceptual audio coding, an audio frame is split into several subframes based on the network configuration such that each packet can be decoded independently at the receiver. Through a subjective comparison category rating (CCR) test, it is discovered that our approach enhances the quality of the decoded audio signal under the lossy packet-switching networks environment.