The Effects of Auditory Short-Term Training in Passive Oddball Paradigm with Novel Stimuli

방정화,한우재 대한청각학회 2013 Journal of Audiology & Otology Vol.17 No.3

Background and Objectives: The purpose of this study was to determine how human neural activity might be changed through auditory short-term training when listening to novel stimuli. Subjects and Methods: Among the twenty young normal hearing adult listeners who participated, ten were randomly assigned to a training group and ten were assigned to a non-training group as a control. Two synthesized novel stimuli were used: /su/ and /∫u/. Both stimuli similarly sounded like /su/, but had two different onset transition frequencies and fricative pole frequencies. In the experiment, behavioral identification test (i.e., /su/ vs. /∫u/) and the mismatch negativity (MMN) were measured before and after training for the training group. To gauge the training effect, the listeners in the training group were taught by discrimination and identification of two novel stimuli for about 20 minutes. Results: The results showed that scores for the behavioral test increased significantly after auditory short-term training. Also, onset latency, duration, and area of the MMN were significantly changed when elicited by the training stimuli. Conclusions: These findings indicated that auditory short-term training could change human neural activity, suggesting future clinical applications for auditory training.

The Cortical Evoked Response Elicited by Nine Plosives in Normal Hearing Listeners

방정화,한우재 대한청각학회 2013 Journal of Audiology & Otology Vol.17 No.3

Background and Objectives: P1-N1-P2 complex reflecting pre-attentive processing of sound presents several temporally overlapping and spatially distributed neural sources in or near primary auditory cortex. This study investigated cortical evoked responses to the P1-N1-P2 complex to determine the perceptual contributions of the acoustic features. Subjects and Methods: Eleven young native-speaking Korean adults with normal hearing participated. The stimuli were three bilabial, three alveolar, and three velar syllables, and each place of articulation had one lax, one tense, and one aspirate syllable as the manner of articulation. Results: The results indicate the cortical responses to the velar syllables significantly differed from the bilabial and alveolar groups at the P1-N1 and N1-P2 interamplitude. However, there is no significant difference in the cortical responses between Korean lax and tense syllables, which is significant for English phonology in terms of voice onset time. Further, the cortical responses to aspirate syllables significantly differed from two other groups in the interamplitude, demonstrating that the /tha/ syllable had the largest response at N1-P2 interamplitude. Conclusions: Different speech sounds evoked different P1-N1-P2 patterns in the place and the manner of articulation in terms of interamplitude, but not of the latency and interlatency although further studies should be followed.

Speech Cue Weighting in Children with Hearing Aids

방정화 한국청각언어재활학회 2010 Audiology and Speech Research Vol.6 No.1

The purpose of the current study was to determine the perceptual weights given to cues for fricative place of articulation by children wearing hearing aids, and whether this differs from children and adults with normal hearing in terms of Developmental Weighting Shift hypothesis. Ten adults and ten 5 to 7-year-old children with normal hearing, and nine children wearing hearing aids participated. Two seven-step continua of synthetic CV syllables were constructed, with frication pole varying from /s/ to /∫/ within the continuum, and appropriate formant transition onset frequency values for /s/ or /∫/ varying across the continua. Results showed that both children and adults gave more perceptual weight to the frication spectral cue than to the formant transition. The weight given the formant transition cue was similar for children and adults, and the degree of cue interaction was similar between children and adults. Children wearing hearing aids did not weight both cues significantly. The results suggest that given these stimuli and analysis methods, children and adult’s weighting of cues for fricative place of articulation are similar. This pattern of results is not consistent with the Developmental Weighting Shift hypothesis that suggests children initially focus more on dynamic than static cues for frication perception. Also, the results of children wearing hearing aids indicated that there were individual differences among hearing impaired children. There were no relationship between speech cue weighting and individual factors.

인공와우 사용자의 심리음향적 음질평가 예비연구

방정화,오수희 한국음향학회 2022 韓國音響學會誌 Vol.41 No.1

Sound quality evaluation is one of the psychoacoustic methods to measure subjective judgements for sound color. The purpose of this study is to investigate sound quality benefits of bimodal users by comparing sound quality scores between bimodal hearing condition and unilateral cochlear implant(CI) condition as a preliminary study. Thirteen bimodal users and seven unilateral CI users were participated in this study. Audiologists performed pure tone and speech audiometry and measured functional gain and real-ear insertion gain. Subjective assessment of sound quality was followed with four sounds including violin sound, male and female voices, and refrigerator noise. Participants judged the sound quality with six sound quality index. Bimodal users showed mean 0.8 points more sound quality improvements in bimodal condition than unilateral CI condition. Group comparison between bimodal and unilateral CI users showed no differences. A follow-up study of sound quality tools and methods should be considered to evaluate subjective bimodal benefits of cochlear implant users. 음질평가는 물리적 음향 자극에 대해 주관적으로 지각되는 음색을 평가한다는 측면에서 심리음향학적 측정과 관련이 있다. 본 논문은 인공와우 사용자의 음질평가를 위한 예비연구로서 바이모달 인공와우 사용자를 대상으로음질평가를 시행하고 인공와우만 착용했을 때와 바이모달을 착용했을 때의 음질평가 차이를 파악하고자 하였다. 총13명의 바이모달 인공와우 사용자와 7명의 편측 인공와우 사용자가 연구에 참여하였고 순음 및 어음 청력검사, 보청기기능이득과 실이삽입이득을 측정하였다. 음질평가에서는 바이올린소리, 남자와 여자 노래소리, 냉장고 소음의 4개 음향자극을 방음실에서 들려주고 6개 음질평가 항목에 대해 0에서 10까지의 척도로 표시하도록 하였다. 검사결과 바이모달 사용자는 편측 인공와우만 착용했을 때보다 바이모달을 착용했을 때 음질평가 5개 항목에서 0.8점 높았고, 바이모달 사용자와 편측 인공와우 사용자 그룹간 비교에서는 두 그룹 사이에 차이를 보이지 않았다. 주관적 측면의 바이모달 혜택 측정을 위해서 좀 더 체계적인 음질평가 도구와 방법에 대한 후속 연구가 필요할 것으로 생각된다.

Weighting of Static and Transition Cues in Voiceless Fricatives and Stops in Children Wearing Cochlear Implants

방정화,Mark Hedrick,Deborah von Hapsburg 대한이비인후과학회 2014 Clinical and Experimental Otorhinolaryngology Vol.7 No.4

Objectives. To determine how normal-hearing adults (NHA), normal-hearing children (NHC) and children wearing cochle- ar implants (CI) differ in the perceptual weight given cues for fricative consonants (having a comparatively long static cue and short transition cue) versus stop consonants (having a comparatively short static cue and long transition cue). Methods. Ten NHA, eleven 5- to 8-year-old NHC and eight 5- to 8-year-old children wearing CI were participated. Frica- tive /su/-/∫u/ and stop /pu/-/tu/ continua were constructed by varying the fricative/burst cue and the F2 onset transi- tion cue. A quantitative method of analysis (analysis of variance model) was used to determine cue weighting and measure cue interaction within groups. Results. For the fricative consonant, all groups gave more weight to the frication spectral cue than to the formant transition. For the voiceless stop consonant, all groups gave more weight to the transition cue than to the burst cue. The CI group showed similar cue weighting strategies to age-matched NHC, but integration of cues by the CI group was not significant. Conclusion. All groups favored the longer-duration cue in both continua to make phonemic judgments. Additionally, devel- opmental patterns across groups were evident. Results of the current study may be used to guide development of CI devices and in efforts to improve speech and language of children wearing CIs.

이야기와 질문을 이용한 청능훈련 도구개발에 관한 연구

임은희,방정화 한국청각언어재활학회 2016 Audiology and Speech Research Vol.12 No.2

Purpose: This study aims to develop auditory training materials using stories for adults and the elderly hearing-impaired listeners. Each story was composed of two sentences and one questionnaire. The new 200 stories are developed which are categorized into four main topics, Korean culture, cuisine, traditional game, and tourist attraction. Twelve normal hearing adults were administrated to verify difficulty of the stories, and 175 out of 200 stories were selected. Methods: To test validity and difficulty of each story and question, a total of 36 subjects with normal hearing listeners participated. Among 175 stories, 79 stories had type I questions, and the 96 stories had type II questions. Each story and the related question were presented at an individual most comfortable level at 6 dB signal-to-noise ratio condition through a loud speaker. Results: The results showed that 160 stories scored 100% of correct response rate, ten stories scored 90-99%, three stories scored 80-89%, and two stories scored 0%. Also, there were no differences between stories with the different type of questions. Conclusion: These results showed that a total of 170 stories are appropriate for the auditory training tool. Future research is needed to demonstrate whether developed training tool is useful to improve communication skills for hearing-impaired listeners.

인공와우 착용 아동의 작업기억, 문장이해력과 문장인지도 간의 관계

박소현,방정화 한국청각언어재활학회 2011 Audiology and Speech Research Vol.7 No.1

This study was to examine the relations among working memory, sentence comprehension and recognition performance by children with a cochlear implant. 20 subjects, divided in two groups, participated; 10 normal hearing children and 10 children with a cochlear implant. Children were all between 6 and 8 years old. The duration of implant use for all children with a cochlear implant was between 4 and 6 years. In the working memory task, children recalled words under three different processing load conditions (i.e., no-load, single-load, and dual-load conditions). In the sentence comprehension task, children listened sentences and chose one picture that explained the sentences. In the sentence recognition task, children listened the target sentence and repeated it or wrote it down. Results of the memory task showed that two groups were not significantly different. However, the children with a cochlear implant showed poorer performance in recalling words in the dual-load condition than those in the other conditions. On the sentence comprehension and recognition tasks, children with a cochlear implant group showed poorer performance than normal hearing children group. In all the three tasks, there were individual variabilities in children with a cochlear implant group. Results of the relationship among three tasks indicated that scores of dual-load condition task were significantly correlated to those of sentence comprehension and recognition tasks in children with a cochlear implant group. Conclusively, findings suggested that children with a cochlear implant have a similar working memory capacity to that of normal hearing children due to early intervention of auditory, speech and language. In addition, findings from children with a cochlear implant group also indicated that their processing capability, especially a complex process, may influence their language ability.

소음 상황에서 건청 성인의 마찰음 지각에 관한 신호 가중치 전략 (Cue Weighting Strategy) 연구

이선미,방정화 한국청각언어재활학회 2012 Audiology and Speech Research Vol.8 No.1

The purpose of this study was to estimate a difference of cue weighting strategies to perceive fricative sounds in normal hearing adults (NHA), across various listening conditions. Eighteen NHA participated to four listening conditions (quiet, 0, -5, and -10 dB SNR). Two seven-step continua of synthetic CV syllables were constructed, with frication pole frequency varied from /s/ to /∫/ within the continuum, and appropriate formant transition values varied across continua. Relative weights applied to the frication, transition, and interaction cues were determined. In quiet condition, NHA gave more perceptul weight to the formant transition cue than to the frication, whereas they gave more perceptual weight to the frication in noisy conditions, rather than the formant transition. Also, in noisy conditions, they attended more to the frication cues than in quiet condition, and at -10 dB SNR condition, cue weighting strategy of fricative perception was significantly different to other conditions. The weight given the degree of cue interaction was not different across four conditions. Results from comparison of this study and the previous study in quiet condition showed that Korean listeners gave more attention to transition cues than American listeners. The results suggest that 1) the longer duration cues were more weighted for perception in difficult listening condition than in easy listening condition, compared to the shorter duration cues and 2) Korean listeners and American listeners used the different cue weighting strategy for perception of fricative sounds.

청성유발반응과 행동검사를 이용한 단기 청능훈련의 학습전이 및 유지 효과에 관한 연구

박수린,방정화 한국청각언어재활학회 2019 Audiology and Speech Research Vol.15 No.4

Purpose: The purpose of this study was to investigate whether short-term auditory training is associated with transfer of learning and retention through behavioral and auditory evoked potential tests the efficacy of short-term auditory training the efficacy. Methods: A total of twenty adult listeners with normal-hearing participated. Among them, eleven participants were randomly assigned as the experimental group. Two pairs of synthesized consonant-vowel (CV) were used, and only one pair of CV was used for the 20-minute auditory training. For the experimental group, behavioral tests and the mismatch negativity (MMN) were assessed using two pairs of CV sounds before and right after the auditory training. For the control group, behavioral and MMN were assessed twice with a 20-minute interval, without any auditory training. Also, all the tests were reassessed in one week after the training only for the experimental group. Results: In the experimental group, scores of the behavioral test increased significantly after the short auditory training for both stimuli sets (trained and untrained CV pairs). Onset latency and duration of MMN were significantly changed when elicited by both stimuli sets. Also, behavioral and MMN results were not significantly changed in one week after the auditory training. There were no significant changes in behavioral scores and onset latency and duration of MMN for the experimental group. Conclusion: The present findings support that short-term auditory training produced significant training effects in terms of transfer of learning and retention.

이명장애지수에 영향을 주는 요인에 대한 분석

류소진,방정화 한국청각언어재활학회 2011 Audiology and Speech Research Vol.7 No.2

The purpose of this study was to analyze the factors related to tinnitus affecting Tinnitus Handicap Inventory (THI) scores. THI, VAS (Visual Analog Scale), Tinnitus history questionnaire, pure-tone audiometry, tinnitogram were conducted with 201 participants who suffered from tinnitus. Among them, 161 subjects had hearing loss. Results indicated that the loudness of tinnitus significantly related to THI scores. However, coefficient of determination was low. THI scores were significantly higher in subjects with unilateral tinnitus than bilateral tinnitus. However, hearing thresholds, gender, onset of tinnitus, type of tinnitus, frequency of tinnitus were not significantly related to THI scores. There was a significant correlation between the subtests of VAS and THI scores. The results of the present study suggest that objective factors related to tinnitus may not predict the degree of tinnitus discomfort and its handicap.