• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.141-146
• /
• 1999

This study aims at establishing an digital signal processing technique to control 3-D sound localization, especially focusing our eyes on the role of information provided by Head-Related Transfer Function(HRTF). In order to clarify the cues to control the auditory distance perception, two conventional models named Hirsch-Tahara model and auditory parallax model were examined. As a result, it was shown that both models have limitations to universally explain the auditory distance perception. Hence, the auditory parallax model was extended so as to apply in broader cases of auditory distance perception. The results of the experiment by simulating HRTFs based on the extented parallax model showed that the cues provided by the new model were almost sufficient to control the perception of auditory distance from an actual sound source located within about 2 m.

• Journal of Biomedical Engineering Research
• /
• v.22 no.3
• /
• pp.241-247
• /
• 2001

ABR(auditory brainstem response) is one of the audiometry which measures objective hearing threshold level by acquiring electric evoked potentials emanated from auditory nerve system responding to an auditory stimulation. However, the obtained potentials which are largely interfered by power line noise, have extremely low SNR, thus ensemble average algorithm is generally used. The purpose of this study was to investigate the effect of iteration number in ensemble average on the reduction of the power line noise. The power line noise was modeled to be a 60 Hz sinusoidal signal and the energy of the modeled signal was calculated when it was averaged. It was verified by simulation that the energy had the periodic zero points for each stimulation rate, and 60 Hz signal induced by the power line was applied to the developed ABR system to confirm that the period of zero energy point was the same with that of the simulation. By the properly selected iteration number, power line noise could be reduced and more reliable ABR could be acquired.

• Journal of Korea Multimedia Society
• /
• v.20 no.12
• /
• pp.1856-1864
• /
• 2017

The ultimate goal of multimedia in bio-signal research is to approach multimedia contents through bio-signal. Hence it is important to interpret user's emotions by analyzing his or her bio-signals. In this paper, we construct ERP task of oddball component to analyze EEG signal between normal stimuli and fear stimuli and measure EEG during ERP task. The results from extracted ERP component show that there is a difference in N200 in visual stimuli, P300 in auditory stimuli, and N100 and P300. Moreover, there are larger changes in audiovisual stimuli, indicating that users recognize greater fear of crime when visual and auditory stimuli are simultaneously presented.

• Journal of Biomedical Engineering Research
• /
• v.15 no.3
• /
• pp.237-244
• /
• 1994

We investigated the qualitive and quantitative properties in EEG signal which responds to auditory stimulus with increaing the sound-cutting frequency from 2 Hz to 20 Hz by 2 Hz step units, by chaotic dynamics. To bigin with, general chaotic properties such as fractal mechanism, 1 If frequency spectrum and positive Lyapunov exponent are discussed in EEG signal. For evoked potential with given auditory stimulus, the route to chaos by bifurcation diagram and the changes in geometrical property of Poincare sections of 2-dimensional psedophase space is observed. For that containing spontaneous potential, seen as the random background signal, the chaotic attractors in 3-dimensional phase space are found containing the same infomation as the above mentioned evoked potential. Finally the chinges of Lyapunov exponent by various sound-cutting frequencies of stimulus and by the various spatial positions (occipital region) in a brain surface to be measured, are illustrated meaningfully.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.41-47
• /
• 2006

In this study, the influences of environmentally friendly visual and auditory information on traffic noise perception were surveyed by the using electroencephalogram Green rural region image and CBD image in urban city were used as visual informations. And traffic noise, signal and environmental music were used to detect the impact on electroencephalogram variance. It was revealed that green rural region image caused a-wave ratio increase about 10% and environmental music increased $\alpha$-wave ratio approximately $40{\sim}50%$. The results of this study improved that environmentally friendly visual and auditory information had an effect on decreasing traffic noise loudness to some extents.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.2 s.119
• /
• pp.160-167
• /
• 2007

In this study, the influences of environmentally friendly visual and auditory information on traffic noise perception were surveyed by the using electroencephalogram. Green rural region image and CBD (central business district) image in urban city were used as visual informations. And traffic noise, signal and environmental music were used to detect the impact on electroencephalogram variance. It was revealed that green rural region image caused ${\alpha}-wave$ ratio increase about 10% and environmental music increased ${\alpha}-wave$ ratio approximately $40{\sim}50%$. The results of this study improved that environmentally friendly visual and auditory information had an effect on decreasing traffic noise loudness to some extents.

• The Journal of the Acoustical Society of Korea
• /
• v.23 no.1
• /
• pp.30-39
• /
• 2004

This study aims at establishing a digital signal processing technique to control 3-D sound localization, especially focusing our ores on the role of information provided by Head-Related Transfer Function (HRTF). In order to clarify the cues to control the auditory distance perception, two conventional models named Hirsch-Tahara model and auditory parallax model were examined. As a result, it was shown that both models have limitations to universally explain the auditory distance perception. Hence, the auditory parallax model was extended so as to apply in broader cases of auditory distance perception. The results of the experiment by simulating HRTFs based on the extended parallax model showed that the cues provided by the new model were almost sufficient to control the perception of auditory distance from an actual sound source located within about 2m.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1997.06a
• /
• pp.13-18
• /
• 1997

Each reproducing speech signal has each particular signal property, because of the processing of encoding and decoding for communications through various media. In this paper, we examine the correlation between speech signal quality and sensory pleasure for the sensory improvement of that signal. In experiments, we evaluate the quality of speech signals through various media by psychological auditory test and physical features of these signals.

• Journal of Broadcast Engineering
• /
• v.6 no.1
• /
• pp.13-20
• /
• 2001

In this paper, we propose a new digital audio watermarking scheme In the cepstrum domain. We insert a digital watermark signal Into the cepstral components of the audio signal using a technique analogous to spread spectrum Communications, hiding a narrow band signal in a wade band channel. In our proposed method, we use pseudo-random sequences to watermark the audio signal. The watermark Is then weighted in the cepstrum domain according to the distribution of cepstral coefficients and the frequency masking characteristics of the human auditory system. The proposed watermark embedding scheme minimizes audibility of the watermark signal. and the embedded watermark is robust to mu1tip1e watermarks, MPEG audio ceding and additive noose.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.35 no.1
• /
• pp.19-24
• /
• 1999

This paper is second part on the auditory thresholds and fish behaviors to the underwater sounds for luring of target species at the set-net in the coast of Cheju. In order to obtain the critical ratio of yellow tails(Seriola quinqueradiata) and the emission level of underwater sound for luring of them, we make experiments to measure the auditory threshold of them using conditioning with electric shock. In state that the white noise with 10dB higher sound pressure level than ambient noise is emitted, the auditory thresholds of yellow tails are measured with 100~116.5dB and they are higher than those in state of no emission of white noise by the masking effects of it. Although sound pressure level of background noise go down, the auditory thresholds go up with frequency above than 300Hz.The critical ratio of yellow-tails in frequency of 80Hz, 100Hz, 200Hz, 500Hz, 800Hz are 46dB, 40dB, 50dB, 52dB, 60dB, 70dB respectively. The sound pressure level of which the signal sound is recognized by yellow tails under the ambient noise is above 100dB and the critical ratio of them is above 40dB.