• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.63-69
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• 2013

The purpose of this study was to evaluate the maximum and optimal listening speed of Korean TTS for the blind. Five blind participants took part in this study. The instruments used in this study were 17 sentence sets (2 sets for an excercise, 10 sets for a repeated test, and 5 sets for a random test), with short meaningful sentences (the same sentences for the repeated test, different sentences for the random test) with 15 differentiated speeds (Range=0.8-3.6, SD=0.2). Each participant's maximum and quickest listening speeds were calculated by objective recall accuracy (determined by the number of correctly recalled syllables/the total number of syllables in a sentence X 100) and subjective recall accuracy (recall accuracy judged by each participant's subjective evaluation). The results showed that the participants' recall accuracy had a tendency to increase as the TTS speed decreased. Participants' subjective recall accuracy was higher than objective recall accuracy in the repeated tests and vice versa in the random tests. The results also revealed that the participants' sentence familiarity had an influence on their Korean TTS listening speed.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.33-41
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• 2013

This study investigated the perceptual and cepstral/spectral characteristics of phonation and their relationships in dysarthria in connected speech. Twenty-two participants were divided into two groups; the eleven dysarthric speakers were paired with matching age and gender healthy control participants. A perceptual evaluation was performed by three speech pathologists using the GRBAS scale to measure the cepstrual/spectral characteristics of phonation between the two groups' connected speech. Correlations showed dysarthric speakers scored significantly worse (with a higher rating) with severities in G (overall dysphonia grade), B (breathiness), and S (strain), while the smoothed prominence of the cepstral peak (CPPs) was significantly lower. The CPPs were significantly correlated with the perceptual ratings, including G, B, and S. The utility of CPPs is supported by its high relationship with perceptually rated dysphonia severity in dysarthric speakers. The receiver operating characteristic (ROC) analysis showed that the threshold of 5.08 dB for the CPPs achieved a good classification for dysarthria, with 63.6% sensitivity and the perfect specificity (100%). Those results indicate the CPPs reliably distinguished between healthy controls and dysarthric speakers. However, the CPP frequency (CPP F0) and low-high spectral ratio (L/H ratio) were not significantly different between the two groups.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.55-60
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• 2013

The purpose of this study was to investigate the acoustic characteristics of crying infants according to the communication intents such as hunger and pain in terms of acoustic differences in the fundamental frequency ($F_0$), jitter, shimmer, noise-to-harmonic ratio(NHR), habitual pitch, and intensity. The subjects were 20 healthy, normal infants, less than seven days old, from the city of Seoul and were born after 38 to 42 weeks(full term) of pregnancy. The sound of crying was recorded for three minutes. The crying due to pain was induced by means of the inborn metabolism error test, whereas the crying due to hunger was verified by means of the rooting reflex by waiting for the designated eating time. The results were as follows: (1) the fundamental frequency, noise-to-harmonic ratio(NHR), and intensity of the infants' crying due to pain was higher than that by hunger, showing a significant difference between the mean values. (2) the infants' crying due to hunger and that by pain did not have a significant difference in the mean jitter and shimmer values but both of them were largely outside of the normal threshold values(jitter by 1.04% and shimmer by 3.81%). This study was significant in the sense that it showed the acoustic characteristics of infants' crying from hunger and pain were very different from each other according to the communication intents in terms of the six acoustic parameters.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.43-51
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• 2013

The purpose of this study is to survey Speech-Language Pathologists' perception on evaluation and treatment of "swallowing disorders". An online questionnaire was sent to the 279 subjects attending undergraduate/graduate programs in speech therapy department and/or SLPs who work in various settings. The survey consisted of three parts: 1) background information and educational/clinical experiences that are associated with dysphagia (swallowing disorder), 2) the current state of diagnosis and treatment of dysphagia of clinical practice (certified SLPs only), 3) the recognition of diagnosis, treatment, education for dysphagia. Each item of the survey was scaled by the participants on a five-point Likert scale of 1 to 5 (1 being not at all and 5 being extremely) or self-reported answers. The results of the survey showed that SLPs have high interest in "swallowing disorder", but most of them regarded them very difficult to diagnose and treat. The reason is that they have not been trained as a swallowing specialist. Therefore it is necessary to provide more opportunities for education and practice to establish the expertise of SLPs.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.39-46
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• 2013

This study examined the perception of two Korean vowels using F1/F2 manipulated synthetic vowels. Previous studies indicated that there is an overlap between the acoustic spaces of Korean /o/ and /u/ in terms of the first two formants. A continuum of eleven synthetic vowels were used as stimuli. The experiment consisted of three tasks: an /o/ identification task (Yes-no), an /u/ identification task (Yes-no), and a forced choice identification task (/o/-/u/). ROC(Receiver Operating Characteristic) analysis and logistic regression were performed to calculate the boundary criterion of the two vowels along the stimulus continuum, and to predict the perceptual judgment on F1 and F2. The result indicated that the location between stimulus no.5 (F1 = 342Hz, F2 = 691Hz) and no.6 (F1 = 336Hz, F2 = 700Hz) was estimated as a perceptual boundary region between /o/ and /u/, while stimulus no.0 (F1=405Hz, F2=666Hz) and no.10 (F1=321Hz, F2=743Hz) were at opposite ends of the continuum. The influence of F2 was predominant over F1 on the perception of the vowel categories.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.11-20
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• 2013

The purpose of this study is to compare the acoustic parameters of English stop consonants at the initial and after-initial-/s/ positions in a message produced by 47 Korean and American speakers in order to provide better pronunciation skills of English stops for Korean learners. A Praat script was developed to obtain voice onset time (VOT), maximum consonant intensity (maxCi), and rate of rise (ROR) from six target words with stops at the positions in the message. Results show that VOT and maxCi were significantly different between the two language groups while ROR wasn't. The Korean speakers generally produced the stop consonants with longer VOTs and higher consonant intensity. From the comparison of consonant groups at the two different positions, the Korean participants did not distinguish them as clearly as the American participants did at the after-initial-/s/ position. Finally a comparison of each language and sex group revealed that the major difference was attributed to stop consonants in the after-/s/ position. The author concluded that Korean speakers should be careful not to produce all the stops with longer VOTs and higher intensity. Further studies would be desirable to examine how Americans evaluate Korean speakers' English proficiency with modified acoustic values of English stops.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.25-32
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• 2013

This research is aimed at finding the acoustic characteristics of different voice rehabilitation techniques, the electrolaryx (EL), standard esophageal (SE), and tracheoesophageal (TE), used on 17 patients with laryngectomees. The analysis of the voice qualities was achieved using MDVP. In order to compare the acoustic characteristics, patients were asked to produce the vowel /a/ sound. The acoustic analysis included fundamental frequency (f0), jitter, shimmer, and noise-to-harmonic ratio (NHR). The main acoustic results showed no significant statistical differences between the average measurements of SE and TE speakers. It was found that the current study showed the same tendency found in previous studies. There was also a significant difference between SE and EL speakers. On the other hand, there were no significant statistical differences between the average measurements of TE and EL speakers on all acoustic measurements. This research will contribute to establishing a baseline related to speech characteristics in voice rehabilitation for patients with laryngectomees. In future, the present findings and issues should be considered in the context of gender. Specifically, the number of women who are diagnosed with laryngeal cancer continues to rise and their acoustic characteristics may indeed differ from those of men.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.21-29
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• 2013

The mismatch negativity (MMN) is known to be a fronto-centrally negative component of the auditory event-related potentials (ERP). $N\ddot{a}\ddot{a}t\ddot{a}nen$ et al. (1997) and Winkler et al. (1999) discuss that MMN acts as a cue to a phoneme perception in the ERP paradigm. In this study a perception experiment based on an ERP paradigm to check how Korean and American English speakers perceive the American English high front vowels was conducted. The study found that the MMN obtained from both Korean and American English speakers was shown around the same time after they heard F1s of English high front vowels. However, when the same groups heard English words containing them, the American English listeners' MMN was shown to be a little faster than the Korean listeners' MMN. These findings suggest that non-speech sounds, such as F1s of vowels, may be processed similarly across speakers of different languages; however, phonemes are processed differently; a native language phoneme is processed faster than a non-native language phoneme.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.3-10
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• 2013

This study investigated the rhythmic accommodation of Korean English learners' interlanguage talk. Twelve Korean speakers, 6 native English speakers and 6 non-native English speakers in London participated in multiple conversations on different topics which produced 36 conversational data in interlanguage talk (ILT) settings. 190 utterances from the 36 conversational data were analyzed to investigate the rhythmic patterns of Korean English learners when they communicated with English speakers with different language backgrounds. Save for the final-syllable, the normalized duration of consecutive syllables was compared in order to derive a variability index (VI). It was found that there was no significant variability in the measurement of the syllable-to-syllable duration for the utterances of Korean English learners, regardless of their interlocutor's language background. Conversely, it was found that there was evidence that Korean English learners showed rhythmic accommodation in ILT when they conversed with non-native English speakers. The speaking rate became significantly slower when Korean English learners talked to non-native English speakers, than when they talked to other Korean English learners. Furthermore, there was a negative correlation between speaking rate and the VI in the utterances of Korean English learners in ILT.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.17-24
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• 2013

This study is aimed at finding out different types of speech characteristics categorized based on voice rehabilitation techniques used on twenty-six patients (all-male) with total or partial laryngectomees. The speech intelligibility of standard esophageal (SE), tracheoesophageal speech (TE), and electriclarynx (EL) was measured by using the CSL and eleven listeners were instructed to rate the speech on a 5-point scale. The vowel space parameters such as vowel space, VAI, FCR, and F2 ratio were measured by averaging 5 repeats of each vowel (/a/, /e/, /i/, /u/) and the results were put into the parameter formula. The results showed significant statistical differences in speech intelligibility and vowel space between SE and TE. The speech intelligibility and vowel space of TE were higher than those of SE or EL and there was a high correlation between speech intelligibility and some parameters (vowel space, VAI, F2 ratio). The results also showed that TE's speech characteristics were most similar to normal groups comparing with SE and EL, but still very deviant in laryngeal speech. This was due to insufficient airflow intake into the esophagus when producing sounds, and because articulation movement was carried out differently among groups. Therefore, these findings will contribute to establishing a baseline related to speech characteristics in voice rehabilitation for patients with alaryngeal speech.