Efficacy of a Closed-Set Auditory Training Protocol on Speech Recognition of Adult Hearing Aid Users / 대한이비인후과학회지

Background and Objectives@#Auditory training involves active listening to auditory stimuli, and it has garnered attention in recent years because it enhances speech-in-noise recognition and the satisfaction of hearing aids. The purpose of this study was to determine the efficacy of a closed-set auditory training protocol for adult hearing aid users. We also evaluated the retention effect of training at a 1-month follow-up test after the completion of training. @*Subjects and Methods@#Twenty-two hearing-impaired listeners who have used bilateral hearing aids for more than two months participated in this study. Out of 22 participants, 12 participants (training group, TG) received an 8-week auditory training while 10 participants did not receive any training (non-training group, NTG). For training, three types of closed-set training materials (environmental sounds, words, and sentences) were used. The training was conducted eight times over eight weeks (one session per week, about one hour per session). The difficulty level was adjusted by controlling the number of closed-set choices and the signal-to-noise ratios. To determine the efficacy of training, open-set speech recognition abilities and subjective hearing aid satisfaction were evaluated. @*Results@#All the open-set speech recognition performances of the TG were enhanced after the closed-set auditory training, while the performance of the NTG was not significantly changed. The auditory training had a positive impact on the TG individuals’ subjective satisfaction of hearing aids. The improvement from training was maintained over one month after the completion of the auditory training. @*Conclusion@#The closed-set auditory training protocol might lead to enhanced speech understanding as well as more satisfaction with hearing aids for adult hearing aid users.

Test-Retest Reliability of Word Recognition Score Using Korean Standard Monosyllabic Word Lists for Adults as a Function of the Number of Test Words

BACKGROUND AND OBJECTIVES: The purpose was to establish the test-retest reliability of word recognition score (WRS) using Korean standard monosyllabic word lists for adults (KS-MWL-A) recently developed based on the international standard for speech audiometry (ISO 8253-3:2012). SUBJECTS AND METHODS: Subjects consisted of 159 adults aged to 18 to 25 years with normal hearing sensitivity. WRSs were obtained in 2 dB steps from the level of speech recognition thresholds to the level of 86% correct responses or greater. After one or two weeks, retest was performed. Correlation, confidence interval (CI) and prediction interval (PI) were calculated for the reliability. RESULTS: Correlation coefficients were 0.88 for 50 test words, 0.76 for 25 and 0.61 for 10 words. Results also showed that 95% CIs and PIs were narrower for 25 and 50 test words than those for 10 test words. CONCLUSIONS: Korean WRS using the KS-MWL-A has high reliability for 25 and 50 test words, but relatively low for 10 words. It suggested that 95% CIs for each test words would be criteria for significant differences in WRS for groups and 95% PIs at each score of WRS could be utilized for a considerable difference for each individual at retest.

Measurement of Acceptable Noise Level with Background Music

BACKGROUND AND OBJECTIVES: Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investigated the relationships between individual ANLs and the familiarity of music samples and between music ANLs and subjective preference. SUBJECTS AND METHODS: Forty-one participants were seperated into two groups according to their ANLs, 29 low-ANL listeners and 12 high-ANL listeners. Using Korean ANL material, the individual ANLs were measured based on the listeners' most comfortable listening level and BNL. The ANLs were measured in six conditions, with different music tempo (fast, slow) and genre (K-pop, pop, classical) in a counterbalanced order. RESULTS: Overall, ANLs did not differ by the tempo of background music, but music genre significantly affected individual ANLs. We observed relatively higher ANLs with K-pop music and relatively lower ANLs with classical music. This tendency was similar in both low-ANL and high-ANL groups. However, the subjective ratings of music familiarity and preference affected ANLs differently for low-ANL and high-ANL groups. In contrast to the low-ANL listeners, the ANLs of the high-ANL listeners were significantly affected by music familiarity and preference. CONCLUSIONS: The genre of background music affected ANLs obtained using background music. The degree of music familiarity and preference appears to be associated with individual susceptibility to background music only for listeners who are greatly annoyed by background noise (high-ANL listeners).

Hearing Thresholds for a Geriatric Population Composed of Korean Males and Females

BACKGROUND AND OBJECTIVES: The purpose of the present study was to provide the hearing threshold levels in the elderly Korean population, and to compare Korean data with that in the International Organization for Standardization (ISO) 7029 (2000). SUBJECTS AND METHODS: Data were collected from a total of 526 ears from 112 males and 151 females aged 60-84 years. All participants were screened otologically by the procedure given in ISO 8253-1 (2010). RESULTS: Results showed that the pure-tone average was gradually elevated with increasing age. The amount of hearing loss was greater in males than in females, and the high frequency hearing thresholds were worse than the low frequency hearing thresholds in males and females. The hearing threshold levels were higher at low frequencies in males and at all frequencies in females than the norms of ISO 7029 (2000). CONCLUSIONS: Results from this study will be partly used for standardization of hearing thresholds as a function of age in Korea and for updating the ISO 7029.

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

OBJECTIVES: To determine how normal-hearing adults (NHA), normal-hearing children (NHC) and children wearing cochlear 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. Fricative /su/-/integralu/ and stop /pu/-/tu/continua were constructed by varying the fricative/burst cue and the F2 onset transition 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, developmental 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.

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

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 /integralu/. 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. /integralu/) 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.