Self-monitoring of listening abilities in normal-hearing children, normal-hearing adults, and children with cochlear implants

Masked Speech Recognition as a Function of Masker Location for Cochlear Implant Users With Single-Sided Deafness

PURPOSE

Cochlear implant (CI) recipients with normal or near normal hearing (NH) in the contralateral ear, referred to as single-sided deafness (SSD), experience significantly better speech recognition in noise with their CI than without it, although reported outcomes vary. One possible explanation for differences in outcomes across studies could be differences in the spatial configurations used to assess performance. This study compared speech recognition for different spatial configurations of the target and masker, with test materials used clinically.

METHOD

Sixteen CI users with SSD completed tasks of masked speech recognition presented in five spatial configurations. The target speech was presented from the front speaker (0° azimuth). The masker was located either 90° or 45° toward the CI-ear or NH-ear or colocated with the target. Materials were the AzBio sentences in a 10-talker masker and the Bamford-Kowal-Bench Speech-in-Noise test (BKB-SIN; four-talker masker). Spatial release from masking (SRM) was computed as the benefit associated with spatial separation relative to the colocated condition.

RESULTS

Performance was significantly better when the masker was separated toward the CI-ear as compared to colocated. No benefit was observed for spatial separations toward the NH-ear. The magnitude of SRM for spatial separations toward the CI-ear was similar for 45° and 90° when tested with the AzBio sentences, but a larger benefit was observed for 90° as compared to 45° for the BKB-SIN.

CONCLUSIONS

Masked speech recognition in CI users with SSD varies as a function of the spatial configuration of the target and masker. Results supported an expansion of the clinical test battery at the study site to assess binaural hearing abilities for CI candidates and recipients with SSD. The revised test battery presents the target from the front speaker and the masker colocated with the target, 90° toward the CI-ear, or 90° toward the NH-ear.

EEG activity evoked in preparation for multi-talker listening by adults and children

Selective attention is critical for successful speech perception because speech is often encountered in the presence of other sounds, including the voices of competing talkers. Faced with the need to attend selectively, listeners perceive speech more accurately when they know characteristics of upcoming talkers before they begin to speak. However, the neural processes that underlie the preparation of selective attention for voices are not fully understood. The current experiments used electroencephalography (EEG) to investigate the time course of brain activity during preparation for an upcoming talker in young adults aged 18-27 years with normal hearing (Experiments 1 and 2) and in typically-developing children aged 7-13 years (Experiment 3). Participants reported key words spoken by a target talker when an opposite-gender distractor talker spoke simultaneously. The two talkers were presented from different spatial locations (±30° azimuth). Before the talkers began to speak, a visual cue indicated either the location (left/right) or the gender (male/female) of the target talker. Adults evoked preparatory EEG activity that started shortly after (<50 ms) the visual cue was presented and was sustained until the talkers began to speak. The location cue evoked similar preparatory activity in Experiments 1 and 2 with different samples of participants. The gender cue did not evoke preparatory activity when it predicted gender only (Experiment 1) but did evoke preparatory activity when it predicted the identity of a specific talker with greater certainty (Experiment 2). Location cues evoked significant preparatory EEG activity in children but gender cues did not. The results provide converging evidence that listeners evoke consistent preparatory brain activity for selecting a talker by their location (regardless of their gender or identity), but not by their gender alone.

Auditory Behavior in Everyday Life (ABEL) questionnaire in Hebrew and in Arabic and its association with clinical tests in cochlear-implanted children

BACKGROUND

The aim of this study was to describe the results of the Auditory Behavior in Everyday Life (ABEL) questionnaire adapted to Hebrew and to Arabic and its association to clinical test results in children with cochlear implants. As assessment of hearing by audiometry does not always adequately reflect performance in daily life, questionnaires have been developed to assess functioning in natural surroundings and to track progress. In order to evaluate cochlear-implanted children's verbal and communicative abilities, the parental ABEL questionnaire was developed in 2002. The advantages of the ABEL questionnaire are that it is intended for a wide age range, is quick to administer, and is filled out by parents themselves.

METHODS

The ABEL questionnaire was translated into Hebrew and into Arabic and routinely used in the clinic. A total of 61 questionnaires were thus filled out by parents of children with cochlear implants (ages 3.9-14.3 years) when they came for routine mapping. Retrospectively, data were analyzed and questionnaire results were compared with performance with the implant on several clinical tests: audiometric thresholds, discrimination (percentage) of vowel-consonant-vowel nonsense syllables, and results of speech perception tests with monosyllabic and bisyllabic words and with sentences in quiet and in noise.

RESULTS

A correlation was found between the different sections of the questionnaire, and age at implantation had a significant effect on questionnaire scores. However, correlations between questionnaire score and clinical tests were found only for speech perception tests in noise and not in quiet or to audiogram and speech reception threshold.

CONCLUSIONS

As has been reported previously, self-evaluation or parental evaluation does not always correlate with all measured results of hearing performance. However, the subjective information collected through questionnaires can be valuable for evaluation of progress, for counseling and rehabilitation training, as well as for mapping.

The development of speech-in-noise perception in Hebrew-speaking school-age children

BACKGROUND

Several studies suggest that auditory perception in general and the perception of speech in noise in particular continue to develop until late childhood or early adolescence. It remains unclear, however, whether this prolonged development results from the maturation of the cognitive factors associated with the performance of auditory tasks or from the slow development of auditory sensory processing.

METHODS

We investigated the perception of monosyllabic words embedded in white noise in Hebrew-speaking school-age children and adults.

RESULTS

Although identification thresholds did not become adult-like until 11 years of age, we found no evidence linking this prolonged development to non-sensory factors associated with performance consistency.

CONCLUSIONS

Therefore, we suggest that similar to the development of amplitude and frequency modulation detection thresholds, this protracted development is related to the maturation of auditory sensory processing.