Error Patterns Analysis of Hearing Aid and Cochlear Implant Users as a Function of Noise

Abstract

Background and ObjectivesNot all impaired listeners may have the same speech perception ability although they will have similar pure-tone threshold and configuration. For this reason, the present study analyzes error patterns in the hearing-impaired compared to normal hearing (NH) listeners as a function of signal-to-noise ratio (SNR).Subjects and MethodsForty-four adults participated: 10 listeners with NH, 20 hearing aids (HA) users and 14 cochlear implants (CI) users. The Korean standardized monosyllables were presented as the stimuli in quiet and three different SNRs. Total error patterns were classified into types of substitution, omission, addition, fail, and no response, using stacked bar plots.ResultsTotal error percent for the three groups significantly increased as the SNRs decreased. For error pattern analysis, the NH group showed substitution errors dominantly regardless of the SNRs compared to the other groups. Both the HA and CI groups had substitution errors that declined, while no response errors appeared as the SNRs increased. The CI group was characterized by lower substitution and higher fail errors than did the HA group. Substitutions of initial and final phonemes in the HA and CI groups were limited by place of articulation errors. However, the HA group had missed consonant place cues, such as formant transitions and stop consonant bursts, whereas the CI group usually had limited confusions of nasal consonants with low frequency characteristics. Interestingly, all three groups showed /k/ addition in the final phoneme, a trend that magnified as noise increased.ConclusionsThe HA and CI groups had their unique error patterns even though the aided thresholds of the two groups were similar. We expect that the results of this study will focus on high error patterns in auditory training of hearing-impaired listeners, resulting in reducing those errors and improving their speech perception ability.

Categorization of sentence recognition for older adults under noisy and time-altered conditions

“…As expected, the number of errors increased in sentence recognition as either the SNR decreased or the rate of speech grew faster. Although the current results were supported by several previous studies, 17 , 18 , 20 they additionally showed a different pattern between the difficult conditions of background noise and time alteration. For instance, the data for background noise demonstrated that the SNHL groups’ speech recognition was significantly more vulnerable to interference from noise than the NHiA groups ( Figure 1 ).…”

“…The noun errors mainly consisted of no response and fail patterns in both the NHiA and SNHL groups, a trend that was magnified as either noise levels increased or speech grew faster. Chun et al 17 reported a similar pattern in a sample that did not include elderly subjects. Their adult group with normal hearing showed substitution errors dominantly regardless of the noise level, but hearing-impaired groups wearing hearing aids and/or having a cochlear implant had remarkable no response error types, rather than declined substitution errors.…”

“…Then, among the nine parts of speech, the noun errors, which represented the most dominant errors of the sentence, were tabulated as seven subgroups of substitution, addition, omission, substitution plus omission, substitution plus addition, fail (or 100% incorrect), and no response, following strategies from a previous study. 17 For example, when the word, ‘C 1 -V-C 2 , V-C 3 ’ (C: consonant, V: vowel), was spoken as ‘C 4 -V-C 2 , V-C 3 ’, this error was defined as ‘substitution.’ However, if a morpheme was skipped (C 4 -V-C 2 , V) or added (C 4 -V-C 2 , C 5 -V-C 3 ), we called those errors ‘substitution plus omission’ and ‘substitution plus addition,’ respectively. ‘Addition’ was the supplement of morpheme, whereas ‘omission’ was the removal of morpheme.…”

“… 14 , 15 Nevertheless, these findings did not connect to improve speech recognition ability in the elderly in terms of aural rehabilitation. In other words, although a few studies have begun to describe phonemic confusion only in hearing-impaired adults, 16 there is still a lack of information about error types and patterns in perceiving speech, 17 , 18 which would describe an additional aspect of speech recognition for the elderly. If their nature is identified, a new strategy for auditory training can be developed in terms of more effective aural rehabilitation.…”

Substitution Patterns of Phoneme Errors in Hearing Aid and Cochlear Implant Users

“…The other method of assessment is to estimate incorrect answers or errors of speech perception and to analyze their patterns [ 5 ]. When conducted with monosyllabic words, for example, the error patterns of hearing aid (HA) and cochlear implant (CI) users were examined under quiet [ 6 ] and noise conditions [ 7 ]. The researchers found that the error patterns of substitution and no response showed much higher numbers than the other patterns, thus suggesting that auditory training could be applied to reduce the highest number of errors first of all-at first.…”