• Journal of the Korea Society of Computer and Information
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• v.22 no.7
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• pp.83-91
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• 2017

In this paper, we propose a thorough solution for adjusting virtual sound field with different kinds of devices and software in preliminary procedure and late stage of music processing. The basic process of music production includes composing, arranging and recording at pre-production stage as well as sound mixing and mastering at post-production stage. At the initial stage of music creation, it should be checked whether the design of virtual sound field, the choice of the tone and the instrument used in the arrangement match the virtual sound field required for the final work. In later recording, mixing and mastering, elaborate adjustments should be done to the virtual sound field. This study also analyzed how to apply the parameter of the effectors to the design and adjustment of the virtual sound field, making it the source of our creation.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.6
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• pp.847-854
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• 2013

This paper implements a smartphone application for sound recording and player of mobile learning. Due to its ubiquitous nature, smartphones could be used anytime anywhere, and because they combine an audio and a microphone, the application for sound recording and player that this paper suggests can be easily and cost effectively developed without additional infrastructure. This paper also explains a technique which processes data of music lyrics. The technique is built on a database technology by using SQLite, a DBMS combined in a platform of android. Thus, as long as the smartphone application for sound recording and player is developed and the mobile phone has sound source files, learners could record their own voices to the sound. Therefore, we expect the learners without additional infrastructure to enable mobile learning.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.174-183
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• 2015

We have conducted a verification test of correlation between bird community indices and bird sound recording results in order to use the equipment which deals with the automatic sound collecting system, the song meter. The study areas include four sites which are Gombaeryoung and Zochimryoung in Jeombongsan Mountain and Jookryoung and Gochiryoung in Sobaeksan National Park. We collected the bird sound data five times using a sound recorder and field survey results in the same place of the study site. As a result of the sound recording from the field survey, the species recorded by three researchers of sound analyst include common resident species or species which have a relatively conspicuous call and song. On the contrary, the species recorded by only one researcher are a relatively rare or inconspicuous species or was familiar with the personal experiences of each researcher. The number of species recorded by only one researcher totaled fourteen species (36.8 %), and that of two researchers totaled twelve species (31.6 %), and that of three researchers totaled twelve species (31.6 %). The correlations of the number of species among three researchers was not significant in some results, but the sum or maximum count of the number of species was useful to estimate a significant correlation between the result of researchers and the indices of field surveys. As a result of correlation analysis by using sound recordings, the maximum number of species among the three researchers significantly correlated with the number of species, the species diversity index and the species abundance index in the field survey at the same site, however it did not correlate with the number of individuals and species evenness index. As a result of sound analysis collected from the stationary sound recording system; song meter, the number of frequencies in bird songs and calls correlated with the number of species in the field survey at the same site. The number of calls and songs decreased as time went by. Finally, we could test the active time range and change the activity strength by using a sound recording system. In particular, that sound recording system is able to collect data in same time and site, so it is expected so that the equipment not only replenish a shortage of researchers and survey periods in field research in a short term monitoring survey, but also be able to acquire statistical objectivity.

• The Journal of Internal Korean Medicine
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• v.36 no.3
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• pp.276-283
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• 2015

Objectives: The purpose of this study is to report bowel sound patterns recorded in 3 diseases associated with structural deformity of the pylorus-duodenum. Methods: : Bowel sound recording is a useful non-invasive tool for the evaluation of gastrointestinal motility. However, the difficulty in manual attachment of the electronic stethoscope on the abdominal wall and noise production against bowel sound signals have prohibited its widespread use. Therefore, I developed a new apparatus that eliminates the noise; it contains a sound absorbing device and a holder for the head of stethoscope. Using the new bowel sound recording system, bowel sounds of the patients were recorded repeatedly. The endoscopic and abdominal computed tomography findings were obtained from other hospitals' medical record, and all patients were confirmed to have structural deformity in the pylorus-duodenum. The records of each patient were compared and assessed. Results: : Patients had either duodenal ulcer scar, pyloric stricture, or far advanced malignant stomach cancer, as diagnosed by the gastroscopy. Their dominant frequency of bowel sound obtained from the new system was checked more than 2 times at regular intervals. All 8 recordings in the 2 patients with duodenal ulcer scar (5 times) or pyloric stricture (3 times) showed a decrease in postprandial than fasting dominant frequency. One patient with stomach cancer showed no significant change between postprandial and fasting states at 2 recordings. Conclusions: The analysis of dominant frequency in bowel sounds can indicate the existence of pyloric obstruction that could delay gastric emptying.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.4
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• pp.289-298
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• 2014

Pass-by noises of various trains were recorded by binaural recorder. The measured noises were evaluated using a sound pressure level and psychoacoustic metrics objectively. To analyze a binaural effect on annoyance that can be caused by train noise, auditory experiments were performed. Through the experiments, the annoyance differences between monaural and binaural train noises, the annoyance differences due to measurement angle and the annoyance differences due to kinds of train and measurement distance were determined. A correlation analysis was conducted to determine which index can affect the annoyance more strongly. As the result, a maximum rate of change of sharpness difference between left and right channels was proposed to predict the annoyance.

• Ocean and Polar Research
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• v.28 no.2
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• pp.145-151
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• 2006

A broadband self-recording hydrophone was developed to conveniently assemble a hydrophone array for use in receiving underwater sound waves. A trigger device with an electromagnetic induction coupler was also developed to control the hydrophone's operation. Main configurations and specifications of the self-recording hydrophone are introduced in this paper. We present experiment results conducted in a water tank to examine the operating behavior of the hydrophone. Some advantages are discussed when the self-recording hydrophones are used to make up a hydrophone array.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.11
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• pp.748-751
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• 2015

Sound Masking System technology as by sound the same on all bands and artificially generates a constant sound shield People want to hear or recognize the people with the noise generated from the interior of the way. Prevent hearing or prevent recognition by using the technology to control the audible frequency band Continue to emit constant and uniform shielding sound audible frequency band Even the security content of speech (20 Hz~20 KHz). That interception laser eavesdropping, internal solicitations, during recording Or delay the decoding was a result of the effect of interference calculated Experience noise disturbance index is applied around the Stress Index is the average index is 10.16 was a luxury for the average index is then applied to the index 3.07 Noise is significantly lower stress level has improved noise conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05b
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• pp.96-102
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• 2003

Today, stage technology is developing highly by application of digital computer. Performance is composed of audio/video and acoustic technology takes very important position in field of stage technology. Generally speaking, four factors of sound are loudness, pitch, sound timbre and duration. Loudness depends on sound pressure level, yet partly related with spectrum and dulation. Pitch depends mainly on frequence and have a relation with sound pressure and duration. sound timbre depends strongly on spectrum and have a relation with frequence. In this paper, I designed a multi-microphone system which can used in broadcasting and performance stage with vicboss 200MHz-VHF wireless microphone and vicboss 900MHz-VHF wireless microphone. I also studied about multi-microphone which can use conveniently in the super play that needs many microphones. If this multi-microphone is prodused, we could expect better sound quality and a big progress in stereo recording technology.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.402-405
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• 2006

The diffuser noise of HVAC(heating ventilating and air-conditioning) uses dB(A) or NC as a indoor noise criteria that ASHRAE represents, and there is no specific guide line for application. According to the previous study, there are some problems like that even though the sound level of sound source is same, the NC shows different values, which makes the noise rating confused. This problem is caused by the frequency characteristics of sound source and its sound level. Therefore, appropriate evaluation method should be considered based on the subjective responses. This study aims to analyze the physical parameters appropriate for the evaluation of HVAC diffuser noise. To achieve this, recording of sound sources, calculation of physical parameters and psycho-acoustic experiment were carried out and the results were derived from the correlation analysis between physical parameters and subjective evaluatio

• ETRI Journal
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• v.22 no.2
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• pp.11-19
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• 2000

If the right and left signals of a binaural sound recording are reproduced through loudspeakers instead of a headphone, they are inevitably mixed during their transmission to the ears of the listener. This degrades the desired realism in the sound reproduction system, which is commonly called 'cross-talk.' A 'cross-talk canceler' that filters binaural signals before they are sent to the sound sources is needed to prevent cross-talk. A cross-talk canceler equalizes the resulting sound around the listener's ears as if the original binaural signal sound is reproduced next to the ears of listener. A cross-talk canceler is also a solution to the problem-how binaural sound is distributed to more than 2 channels that drive sound sources. This paper presents an effective way of building a cross-talk canceler in which geometric information, including locations of the listener and multiple loudspeakers, is divided into angular information and distance information. The presented method makes a database in an off-line way using an adaptive filtering technique and Head Related Transfer Functions. Though the database is mainly concerned about the situation where loudspeakers are located on a standard radius from the listener, it can be used for general radius cases after a distance compensation process, which requires a small amount of computation. Issues related to inverting a system to build a cross-talk canceler are discussed and numerical results explaining the preferred configuration of a sound reproduction system for stereo loudspeakers are presented.