• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.99-105
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• 2011

The treatment for patients with mutational dysphonia typically is useful with vegetative phonation, but has not yet been studied. This study attempts to identify the effect of $SKTCLP^{(R)}$ using throat clearing and laughing in patients with mutational dysphonia. The study, which was designed by the author, included 26 patients aged from 14 to 32 years (mean: 18.7 years) who had been diagnosed with mutational dysphonia between January 2007 and June 2010. Voice therapy for these patients included $SKTCLP^{(R)}$, ranging from two to seven sessions (mean: 3.8 sessions). Results were evaluated by videostroboscopy, perceptual evaluation of GRBAS scale, aerodynamic test, and acoustic analysis before and after therapy. Most patients could phonate with low pitch from the beginning and sustain with normal pitch sound in the last session. We had found that glottic gap reduced after therapy and anterior-posterior compression of superior laryngeal part at the first time, and these patients had complete closure of the glottis after treatment. The results of acoustic and aerodynamic measures after treatment indicated significant decreases in Fo, Jitter, Shimmer, SFF, and SPI, and increases in MPT, Psub, and vocal efficiency (p<.05). $SKTCLP^{(R)}$ may be a useful treatment method in managing mutational dysphonia. We can suggest this technique may be useful in improving the voice quality of other functional dysphonia having glottal chink or functional aphonia.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1196-1203
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• 2011

The reduced frequency selectivity is a typical phenomenon of sensorineural hearing loss. In this paper, we compared two modeling methods for reduced frequency selectivity of hearing impaired people. The two models of reduced frequency selectivity were made using LPC(linear prediction coding) algorithm and bandwidth control algorithm based on ERB(equivalent rectangular bandwidth) of auditory filter, respectively. To compare the effectiveness of two models, we compared the result of PESQ (perceptual evaluation of speech quality) and LLR(log likelihood ratio) using 36 Korean words of two syllables. To verify the effect on noise condition, we mixed white and babble noise with 0dB and -3dB SNR to speech words. As the result, it is confirmed that the PESQ score of bandwidth control algorithm is higher than the score of LPC algorithm, on the other hands, and the LLR score of LPC algorithm is lower than the score of bandwidth control algorithm. It means that both non-linearity and widen auditory filter characteristics caused by reduced frequency selectivity could be more reflected in bandwidth control algorithm than in LPC algorithm.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.344-349
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• 2017

Suspension noise from under a passenger car is one of the important factors that impact the perceptual quality for drivers. However, it is difficult to validate this by component level testing in the early stage of development, because suspension noise caused by interaction of the related parts has been found at saleable vehicles late during development or at the manufacturing stage, when many customers have already filed for claims. This study proposed a validation testing under research by the DFSS process that enables reproduction of vehicle level noise by component level testing using a shock absorber with the related parts, such as urethane bumper and top mount. This study also developed a compromised test matrix while analyzing the noise factors through experimental design and analysis of variance to determine what factors can affect noise. Based on this study, we expect that the vehicle level and customer claim can be validated during initial development timing by a more reliable component noise validation test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.352-360
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• 2010

Supporting user perceptual QoE-guaranteed IP-based multimedia service such as IPTV and Mobile IPTV, we represent an efficient QoE-aware transport stream assessment schemes to apply realtime mobile IPTV's contents distorted by various network errors such as bandwidth, delay, jitter, and packet loss. This paper proposes in detail an efficient matching and QoE-aware measurement methods. The brightness of the digitized contents per each frames of transport streams is used and applied to reduced-reference method. The hybrid video quality metric is designed by QoE-indicators such as blur, block, edge busyness, and color error. We compare original with processed source to evaluate them in a high precision degree of accuracy.

• Speech Sciences
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• v.13 no.1
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• pp.95-105
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• 2006

The primary goal of therapeutic intervention in dysarthric speakers is to increase the speech intelligibility. Decision of critical features to increase the intelligibility is very important in speech therapy. The purpose of this study is to know the effects of pitch increasing training (PIT) on speech of a subject with Parkinson's disease (PD). The PIT program is focused on increasing pitch while a vowel is sustained with the same loudness. The loudness level is somewhat higher than that of the habitual loudness. A 67-year-old female with PD participated in the study. Speech therapy was conducted for 4 sessions (200 minutes) for one week. Before and after the treatment, acoustic, perceptual and speech naturalness evaluation was peformed for data analysis. Speech and voice satisfaction index (SVSI) was obtained after the treatment. Results showed Improvements in voice quality and speech naturalness. In addition, the patient's satisfaction ratings (SVSI) indicated a positive relationship between improved speech production and their (the patient and care-givers) satisfaction.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.71-78
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• 2013

The purpose of this study was to compare the acoustic voice outcomes of children with cochlear implant to those of children with normal hearing. Participants were 41 children using unilateral cochlear implant (18 males and 23 females), and children with normal hearing from the same age and sex. Mean age of implantation was approximately 3 years old, mean duration of implant use was 4 years in CI group. Acoustic analyses were performed using MDVP of CSL. Speech samples were 3 sustained vowels, /a, i, u/. 9 parameters (F0, Fhi, Flo, Jitter, Shimmer, vF0, vAm, NHR, and SPI) were analyzed. Children with CI did not show the significant differences in those parameters after the vowel /a/ phonation. Meanwhile, there were significantly different results in F0, Fhi, vF0, and SPI after /i, u/ phonation. These results revealed that differences of voice characteristics in children with CI compare to children with NH persist regarding vowel context. It suggests that high vowels would recommend as speech samples for acoustic evaluation. Futhermore perceptual analysis and speech therapy for phonation control would be necessary for children with CI.

• ETRI Journal
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• v.31 no.4
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• pp.408-418
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• 2009

Adopting an encryption function in voice over Wi-Fi service incurs problems such as additional power consumption and degradation of communication quality. To overcome these problems, a partial encryption (PE) algorithm for compressed speech was recently introduced. However, from the security point of view, the partial encryption sets (PESs) of the conventional PE algorithm still have much room for improvement. This paper proposes a new selection method for finding a smaller PES while maintaining the security level of encrypted speech. The proposed PES selection method employs the perceptual evaluation of the speech quality (PESQ) algorithm to objectively measure the distortion of speech. The proposed method is applied to the ITU-T G.729 speech codec, and content protection capability is verified by a range of tests and a reconstruction attack. The experimental results show that encrypting only 20% of the compressed bitstream is sufficient to effectively hide the entire content of speech.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.307-310
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• 2007

In this paper, a packet loss concealment (PLC) algorithm for CELP-type speech coders is proposed to improve the quality of decoded speech under a burst packet loss condition. The proposed algorithm is based on the recovery of voiced excitation using an estimate of the voicing probability and the generation of random excitation by permutating the previously decoded excitation. The voicing probability is estimated from the correlation using the previous correctly decoded excitation and pitch. The proposed algorithm is implemented as a PLC algorithm for G.729 and its performance is compared with PLC employed in G.729 by means of perceptual evaluation of speech quality (PESQ) and an A-B preference test under the random and burst packet losses with rates of 3% and 5%. It is shown that the proposed algorithm provides better speech quality than the PLC of G.729, especially under burst pack losses.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.1
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• pp.104-112
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• 2000

An evaluation of voice disorder has two methods. One is a perceptual analysis and the other is an acoustic analysis. All of these methods are just focused on sustained vowel. The analysis of conversational speech levels in voice disorder has not been achieved enough. The purpose of the present study is to compare two syllable words and sustained vowel in the vocal polyp patients and normal male speakers and to be applied on the vocal assessment and the voice therapy as a basic data. fifteen male patients with vocal polyp were the subject group. Fifteen healthy male were the control group for this study. The voices of the subject and control group, saved in MDVP of CSL were analyzed by its own analysis program. As a results, in subject group, the voice qualities between the vowel following lenis stop and the sustained vowel had no differences, and the voice qualities were different significantly between the vowel following heavily aspirated stop and the sustained vowel. In the control group the vowel fllowing stops and sustained vowel had also many differences in their voice quality, especially significant between the vowel following glottal stop and e sustained vowel.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.48-54
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• 2012

The quality of real-time voice communication over Internet Protocol networks based on telematics is affected by network impairments such as delays, jitters, and packet loss. To resolve this issue, this paper proposes a receiver-based enhancing method of VoIP speech quality. The proposed method enables users to deliver high-quality voice using playout control and signal reconstruction, which consists of concealment of lost packets, adaptive playout-buffer scheduling using active jitter estimation, and smooth interpolation between two signals in a transition region. The proposed algorithm achieves higher Perceptual Evaluation of Speech Quality (PESQ) values and low buffering delay than the reference algorithm.