Mismatched response predicts behavioral speech discrimination outcomes in infants with hearing loss and normal hearing

The mismatch response in normal hearing adults: a performance comparison with stimuli relevant for objective validation of hearing aid fittings

OBJECTIVE

A long-standing observation is that the Mismatch Response (MMR) has the potential to offer a clinically feasible index of sound discrimination. However, findings that positively identify MMRs at the individual level have been mixed, even for those who are normally hearing and who can discriminate sounds behaviourally. This complicates interpretation when an MMR is not observed. The objective of this study was to determine the reliability of the MMR using an optimised paradigm and a range of stimuli relevant to audiological applications in relation to objective verification of hearing aid fittings.

DESIGN

MMRs were measured using an optimised 3-deviant paradigm in response to a range of sounds designed for aided and unaided sound field assessments, including complex tones (CTs) and speech-like signals.

STUDY SAMPLE

Seventeen normally hearing adults (18-56 years).

RESULTS

The most robust MMRs were recorded in response to CTs; responses were positively identified in 50 out of 51 instances (98%), assessed via objective Hotelling's T2 bias-free statistical analyses.

CONCLUSIONS

The results indicate that CTs in conjunction with optimised recording and analysis parameters offer the potential to elicit robust MMRs, supporting future utilisation of MMRs for clinical audiological applications.

EEG Alpha Band Responses Reveal Amplification Benefits in Infants with Hearing Loss

Our objective was to examine the effects of hearing aid amplification on auditory detection and discrimination in infants who were hard of hearing (IHH) using a physiological measure of auditory perception. We recorded EEG from 41 sleeping IHH aged 1.04 to 5.62 months while presenting auditory stimuli in a mismatch response paradigm. Responses were recorded during two listening conditions for each participant: aided and unaided. Temporal envelopes of the mismatch response in the EEG alpha band (6-12 Hz) were extracted from the latent, time-frequency transformed data. Aided alpha band responses were greater than unaided responses for the deviant trials but were not different for the standard trials. Responses to the deviant trials were greater than responses to the standard trials for the aided conditions but were not different for the unaided conditions. These results suggest that the alpha band mismatch can be used to examine both detection and discrimination of speech and non-speech sounds in IHH. With further study, the alpha band mismatch could expand and refine our abilities to validate hearing aid fittings at younger ages than current clinical protocols allow.

Pre-attentive fundamental frequency processing in Mandarin-speaking children with cochlear implants as revealed by the peak latency of positive mismatch response

Introduction

Fundamental frequency (F0) serves as the primary acoustic cue for Mandarin tone perception. Recent behavioral studies suggest that F0 information may be differently processed between Mandarin-speaking normal-hearing (NH) children and children with cochlear implants (CIs), which may partially explain the unsatisfactory outcome of lexical tone recognition using CIs with tonal language-oriented speech processing strategies. The aim of the current study was to provide neural evidence of F0 processing in Mandarin-speaking kindergarten-aged children with CIs compared with NH children.

Methods

Positive mismatch responses (p-MMRs) to the change of the two acoustic dimensions of F0 (F0 contour and F0 level) in Mandarin-speaking kindergarten-aged children with CIs (n = 19) and their age-matched NH peers (n = 21).

Results

The two groups of children did not show any significant difference on the mean amplitude of p-MMR to either F0 contour or F0 level change. While the CI group exhibited a significantly shorter peak latency of p-MMR to F0 contour change than to F0 level change, an opposite pattern was observed in the NH group.

Discussion

This study revealed a higher sensitivity to F0 contour change than to F0 level change in children with CIs, which was different from that in NH children. The neural evidence of discrepant F0 processing between children with CIs and NH children in this study was consistent with the previously reported behavioral findings and may serve as a reference for the development and improvement of tonal language-oriented speech processing strategies.

Behavioral and Neural Assessments of Auditory Skill Development After Hearing Instrument Fitting in Children: Case Reports and Clinical Implications

PURPOSE

The purpose of this study was to comprehensively monitor the auditory skill development of children with hearing loss after hearing instrument fitting, and a battery of four assessments was proposed.

METHOD

This battery was designed to fill the gap in speech discrimination in clinically available evaluations. The battery includes both behavioral and neural assessments. On the other hand, both tests in structured settings (sound-treated booth) and daily life were included in the battery. The four assessments include visual reinforced infant speech discrimination (VRISD), cortical auditory evoked potentials (CAEP), Auditory Skills Checklist (ASC), and Parents' Evaluation of Aural/Oral Performance of Children (PEACH).

RESULTS

Two cases were reported, and their clinical implications were discussed.

CONCLUSIONS

The proposed comprehensive assessment battery is suitable for evaluating children who are developmentally appropriate for visual reinforcement audiometry. More importantly, the VRISD assessment fills in the current gap, which is the discrimination stage, for the available clinical tests for assessing auditory developmental stages.

Relationship between Behavioral Infant Speech Perception and Hearing Age for Children with Hearing Loss

(1) Background: Research has demonstrated that early intervention for children who are hard-of-hearing (CHH) facilitates improved language development. Early speech perception abilities may impact CHH outcomes and guide future intervention. The objective of this study was to examine the use of a conditioned head turn (CHT) task as a measure of speech discrimination in CHH using a clinically feasible protocol. (2) Methods: Speech perception was assessed for a consonant and vowel contrast among 57 CHH and 70 children with normal hearing (CNH) aged 5–17 months using a CHT paradigm. (3) Results: Regardless of hearing status, 74% of CHH and 77% of CNH could discriminate /a-i/, and 55% of CHH and 56% of CNH could discriminate /ba-da/. Regression models revealed that both CHH and CNH performed better on /ba-da/ at 70 dBA compared to 50 dBA. Performance by hearing age showed no speech perception differences for CNH and children with mild hearing loss for either contrast. However, children with hearing losses ≥ 41 dB HL performed significantly poorer than CNH for /a-i/. (4) Conclusions: This study demonstrates the clinical feasibility of assessing early speech perception in infants with hearing loss and replicates previous findings of speech perception abilities among CHH and CNH.