Effects of Redundancy Changes in Time and Frequency on Discriminating Monosyllabic
Words(CVC) under Ipsilateral/Contralateral Background Noise Conditions

Kang, Sunyoung; Lim, Dukhwan

doi:2007.3.1.43

Audiol > Volume 3(1); 2007 > Article

Research Paper

Audiology 2007;3(1): 43-51.
Published online: June 30, 2007.
doi: http://doi.org/10.21848/audiol.2007.3.1.43

시간 및 주파수 정보 변형이 동측 및 대측 소음조건에서 혼동하기 쉬운 단음절 단어(CVC) 변별에 미치는 영향

강선영¹, 임덕환²

¹분당차병원 이비인후과
²한림대학교 언어청각학부 청각학과 청각언어연구소

Effects of Redundancy Changes in Time and Frequency on Discriminating Monosyllabic Words(CVC) under Ipsilateral/Contralateral Background Noise Conditions

Sunyoung Kang¹, Dukhwan Lim²

¹Department of Otolaryngology, Bundang Cha Hospital, Seongnam, Korea
²Section of Audiology and Audiology and Speech Pathology Research Institute, Chuncheon, Korea

Correspondence

Dukhwan Lim ,Tel: (033) 248-2217, Fax: (02) 6280-9133, Email: dlim@hallym.ac.kr

Received: January 9, 2007; Accepted: February 28, 2007. Published online: June 30, 2007.

ABSTRACT

The purpose of this study was to analyze the effects of redundancy changes in time and frequency domains (compression/expansion and high/low pass filtering) on discriminating monosyllabic words (CVC) under various signal to noise ratios (No noise, 10 dB, 0 dB, -10 dB SNR). Ten normal adult subjects participated in the study and three groups of “gom/gong”, “mal/bal”, and “sun/soon” sets were used as CVC word lists. In general, as the level of noise was increased, the ability of discriminating the listed set of words was deteriorated and this tendency was even pronounced under ipsilateral noise presentations. Changes in time and frequency domain clearly affected the discrimination performances of three test sets in conjunction with various levels of noise (SNR). The following main results were obtained from this experiment. 1) In ipsilateral presentation of noise, the lowest discrimination score was obtained in “gom/gong” set under the HIGH condition of redundancy change (i.e. highpass filtering in frequency). 2) In contralateral presentation of noise, the lowest discrimination score was recorded in “gom/gong” set as well and no statistically significant differences were observed in right and left sides of noise stimulation. 3) Even in normal subjects, discrimination of ending consonants (such as in gom/gong set) and initial consonants (such as in mal/bal set), and intermediate vowels (such as in sun/soon) were significantly influenced by the level of noise. Thus, in these data, it was suggested that the effects of the noise, together with time and frequency alterations, were critical in discriminating these CVC words. In conclusion, temporal changes in FAST/SLOW modes and spectral changes in LOW/HIGH modes could interact with the levels of SNR and the resultant combinations seemed to play critical roles in similar frequency bands in related phonemes. This kind of clinical data could be valuable in auditory training and rehabilitation for the hearing impaired.

Key Words: Monosyllabic words·Ipsilateral noise·Contralateral noise·Redundancy change.

중심단어: 단음절· 동측소음· 대측소음· 잉여정보변화.