• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1799-1802
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• 2002

This paper proposes an improved method for formant frequencies estimation based on the complex autocorrelation function of the speech signal. Instead of using the incoming signal as an input fur the LPC analysis, the analytic signal of the autocorrelation function of the speech signal is computed and itself used as an input for the LPC analysis. Due to the properties of the analytic signal, which occupies half of the bandwidth of the original signal, the required model order for the LPC analysis is halved. The accuracy of the proposed method in noisy environments is examined on five natural vowels. The effectiveness of the proposed method is shown by the estimated spectral shapes and the estimation errors of the formant frequencies.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.137-142
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• 2012

The aim of this study is to investigate the usefulness of the multiple-choice name matching test (MC-NMT) in adults with aphasia by comparing the Korean version of the Boston Naming Test (K-BNT) and subsets of the Korean version of the Western Aphasia Battery (K-WAB). Thirty-nine patients who suffer from aphasia participated in the study. All patients were examined by the K-BNT, MC-NMT and K-WAB. The MC-NMT consisted of the 30 original BNT object stimuli which were presented with four response choices (written words) with similar frequency, including one correct and three incorrect responses. Cards containing the drawings were presented to the patient one at time. An item was passed if the patient chose the correct response within 10 seconds. We subdivided two groups into a total group and a low K-BNT group (at and below 15 points). We evaluated the correlation between the K-BNT, MC-NMT score and production, naming, repetition, comprehension, reading and writing scores in subsets of the K-WAB. There was a highly positive correlation between the K-BNT score and naming score of the K-WAB in total patients. However, the MC-NMT was highly correlated with reading scores in the K-WAB. In low score K-BNT patients, the K-BNT strongly correlated with production, naming and repetition scores of the K-WAB. These findings mean that K-BNT reflects motor language function. However, the MC-NMT was strong correlated comprehension, reading and writing of the K-WAB. This finding reflects sensory language function. We suggest that the combination of K-BNT and newly developed MC-NMT will be useful to evaluate speech functions in aphasic patients.

• Korean Journal of Cleft Lip And Palate
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• v.8 no.1
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• pp.39-44
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• 2005

Velopharyngeal incompetence(VPI) is that soft palate and muscle of posterolateral pharyngeal wall can not close velopharyngeal port properly. Thing that prior to treatment for patient with VPI is to evaluation about nasopharyngeal closing function. This data is important for making a treatment plan and assesment of treatment effect to improve nasopharyngeal closing function. There are two ways of VPI assessment. The one is subjective method by auditory finding, the other is objective method by using equipment for language test. Using only subjective way is not adequate for evaluation of VPI because of low trust, so doing both two methods simultaneously help to make a diagnosis and assessment exactly. CPAP is effective method to treat hypernasality. This new treatment technique intensify oropharyngeal muscle for nasopharyngeal closing by direct resistance training. Becase conventional treatments have limitation, so many research about treatment effectiveness of CPAP are being studied. This study aims that we compare our result from Korean VPI patients with result about treatment effect in other advanced country, to make CPAP Treatment Questionares and to find ways that improve oropharyngeal closing function an[1 maximally increase language treatment effect.

• Archives of Plastic Surgery
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• v.39 no.1
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• pp.25-30
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• 2012

Background : The soft palate functions as a valve and helps generate the oral pressure required for normal speech resonance. Speech problems and nasal regurgitation can result from a soft palatal defect. Reduction of the size of the velopharyngeal orifice is required to compensate for the lack of mobility in a reconstructed soft palate. We suggest a large volume folded free flap for reduction of the caliber and a palmaris longus tendon sling for suspension of the reconstructed palate. Methods : Six patients had total soft palate resection for tonsillar cancer and reconstruction with a large volume folded radial forearm free flap combined with a palmaris longus sling. A single surgeon and speech therapist examined the patients with three standardized speech assessment tools: nasometer test, consonant articulation test, and speech acuity test performed for speech evaluation. Results : Mean nasalance score was 76.20% for sentences with nasal sounds and 43.60% for sentences with oral sounds. Hypernasality was seen for oral sound sentences. The mean score of the picture consonant articulation test was 84% (range, 63% to 100%). The mean score of the speech acuity test was 5.84 (range, 5 to 6). These mean ratings represent a satisfactory level of speech function. Conclusions : The large volume folded free flap with a palmaris longus tendon sling for total soft palate reconstruction resulted in satisfactory prognosis for speech despite moderate hypernasality.

• 대한두경부종양학회:학술대회논문집
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• 2007.05a
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• pp.80-84
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• 2007

Background and Objectives : The radial forearm free flap is a useful reconstructive method of surgical defects after oral and oropharyngeal tumor resection. We evaluated the swallowing and speech outcomes of radial forearm free flap reconstruction for oral and oropharyngeal cancers. Materials and Methods : We retrospectively reviewed clinical data of 84 patients who underwent reconstructive surgery for oral or oropharyngeal cancer using radial forearm free flap from August 1994 to January 2007. Modified barium swallowing (MBS) was done in 100 patients and speech-language assessment was done in 23 patients by a speech-language pathologist. Results were analyzed according to the swallowing functions and the speech-language assessments. Results : According to the results of MBS which was done postoperatively, aspiration occurred in three patients and velopharyngeal insufficiency occurred in four patients who had been reconstructed with multilobed free flap due to large mucosal defects. There was one patient who exhibited severe articulation impairment out of 23 patients. However, 19 patients out of 23 patients showed excellent intelligibility in speech. Conclusion : We concluded that the radial forearm free flap technique is an excellent reconstructive method for the restoration of palatal and pharyngeal function in oral and oropharyngeal cancer patients.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.4
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• pp.363-371
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• 2010

In an effort to enhance the quality of feature vector classification and thereby reduce the recognition error rate for the speaker-independent speech recognition, we study the effect of spectral tilt on the Fourier magnitude spectrum en route to the extraction of MFCC. The effect of FIR filtering on the speech signal on the speech recognition is also investigated in parallel. Evaluation of the proposed methods are performed by two independent ways of the Fisher discriminant objective function and speech recognition test by hidden Markov model with fuzzy vector quantization. From the experiments, the recognition error rate is found to show about 10% relative improvements over the conventional method by an appropriate choice of the tilt factor.

• Speech Sciences
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• v.15 no.3
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• pp.103-116
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• 2008

Cerebral palsy children represent abnormal vocalization pattern caused by respiration problem and paralyzed oral motor muscle that are the basics of speech production. Thus, this study examined the effect of respiration and articulator training programs on the basic ability of speech production in CP children. The subjects of this study were 4 children with 3 of spastic CP and 1 of ataxia CP. The respiration and articulator program was conducted in 30 sessions for 30 minutes each. Pre-test was administered twice before the program, ongoing test was administered every 5 session during the period of experiment, and post-test was administered twice. The program included speech production such as respiration training, lips, jaw, cheek, and tongue exercise, and velopharyngeal training, and related articulator training. The following results were obtained. First, all subject children were less than 5 seconds in maximum phonation time before the experiment and 2 were improved by more than 4$\sim$5 seconds during the experiment, but 2 had relatively low rising width. Second, while children with less than 30dB before the experiment became bigger in strength during the experiment, children with more than 35dB before the experiment showed a minor change. Subject child 4 had lower vocal strength in the post-test period. Finally, although each subject had individual difference in syllable diadochokinetic ability, the function was improved and the number of repetition in one respiration was also increased.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.2
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• pp.140-148
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• 1999

The use of obturator is the prosthetic rehabilitation approach for restoration of the defected maxillary shape and function for the patients with palatal defect. The obturator can change the shape of vocal tract and nasality, but few reports on the effects of the change were presented. So, the authors performed the experimental study to compare the difference between the sizes of vowel triangles produced by maxillectomized patients before and after obturator-wearing and to consider how much improvement in speech intelligibility can be expected by obturator wearing. The 8 patients who were totally maxillectomized due to palatal cancer were participated as subjects. They produced 5 vowels(/a/, /i/, /u/, /e/, /o/) before and after obturator-wearing. The formants of the vowels were analyzed by the spectrogram of CSL, and their speech intelligibility were judged by normal 8 listeners. As results, the frequency of the first and the second formant showed no significant difference between the articulation before and after wearing, but the comparison of the sizes of vowel triangles, related with the speech intelligibility, showed significant difference. The vowel triangle of the articulation after wearing was larger than that of the articulation before wearing. /i/ showed the lowest speech intelligibility score among the vowel articulation before wearing. After wearing obturators, their scores increased on the whole, especially, in /a/, but the intelligibility of /u/ decreased after wearing.

• Speech Sciences
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• v.4 no.2
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• pp.69-89
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• 1998

The aim of this study is to develop an objectively method of speech evaluation for children with cleft palates. To assess velopharyngeal function, Visi-Pitch, Computerized Speech Lab. (CSL), Nasometer and Palatometer were used for this study. Acoustic parameters were measured depending on the diagnostic instruments: Pitch (Hz), sound pressure level (dB), jitter (%) and diadochokinetic rate by Visi-Pitch, VOT and vowels formant ($F_1\;&\;F_2$) by a Spectrography and the degree of hypernasality by Nasometer. In addition, Palatometer was used to find the lingual-palatal patterns of cleft palate. Ten children with cleft palates and fifty normal children participated in the experiment. The results are as follows: (1) Higher nasalance of children with cleft palates showed the resonance disorder. (2) The cleft palate showed palatal misarticulation and lateral misarticulation on the palatogram. (3) Children with cleft palates showed the phonatory and respiratory problems. The duration of sustained vowels in children with cleft palates was shorter than in the control groups. The pitch of children with cleft palates was higher than in the control groups. However, intensity, jitter and diadochokinetic rate of children with cleft palates were lower than in the control group. (4) On the Spectrogram, the VOT of children with cleft palates was longer than control group. $F_1\;&\;F_2$ were lower than in the control group.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.337-338
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• 2000

The perceptual filter for speech enhancement was analytically derived where the frequency content of the input noisy signal was made the same as that of the estimated clean signal in auditory domain. However, the analytical derivation should rely on the deconvolution associated with the spreading function in the psychoacoustic model, which results in an ill-conditioned problem. In order to cope with the problem associated with the deconvolution, we propose a novel psychoacoustic model based speech enhancement filter whose principle is the same as the perceptual filter, however the filter is derived by a constrained optimization which provides solutions to the ill-conditioned problem.