Using the Mismatch Negativity to Evaluate Hearing Aid Directional Enhancement Based on Multistream Architecture.

Objectives: To evaluate whether hearing aid directivity based on multistream architecture (MSA) might enhance the mismatch negativity (MMN) evoked by phonemic contrasts in noise.

Design: Single-blind within-subjects design. Fifteen older adults (mean age = 72.

Acoustic- Versus Intelligibility-Based Assessment of Subjective Listening Difficulty Measured With the Repeat-Recall Test.

Objectives: To contrast interpretations of listening effort ratings when judged against acoustic- versus intelligibility-based normative references.

Design: Existing data collected from 66 normal-hearing adult listeners, comprising 2730 trials of the Repeat-Recall Test, were used to establish norms of subjective listening effort ratings for six ranges of intelligibility. Data from 21 aided hearing-impaired listeners were then used to contrast intelligibility-based norms against acoustic-based norms when interpreting listening effort ratings measured in omnidirectional and directional microphone conditions.

Using Alpha-Band Power to Evaluate Hearing Aid Directionality Based on Multistream Architecture.

Purpose: The aim of the study was to evaluate whether behavioral speech-in-noise (SiN) benefits of hearing aid directivity based on multistream architecture (MSA) might result in reduced electroencephalographic activity in the alpha-band, as is often associated with task difficulty.

Method: A single-blind within-subject design was used in this study. Thirteen older adults ( = 73.

Alpha-Band Dynamics of Hearing Aid Wearers Performing the Repeat-Recall Test (RRT).

This study measured electroencephalographic activity in the alpha band, often associated with task difficulty, to physiologically validate self-reported effort ratings from older hearing-impaired listeners performing the Repeat-Recall Test (RRT)-an integrative multipart assessment of speech-in-noise performance, context use, and auditory working memory. Following a single-blind within-subjects design, 16 older listeners (mean age = 71 years, SD = 13, 9 female) with a moderate-to-severe degree of bilateral sensorineural hearing loss performed the RRT while wearing hearing aids at four fixed signal-to-noise ratios (SNRs) of -5, 0, 5, and 10 dB. Performance and subjective ratings of listening effort were assessed for complementary versions of the RRT materials with high/low availability of semantic context.

Cortical sensory gating and reactions to dynamic speech-in-noise in older normal-hearing and hearing-impaired adults.

Objective: To examine whether cortical sensory gating predicts how older adults with and without hearing loss perform the Tracking of Noise Tolerance (TNT) test.

Design: Single-blind mixed design. TNT performance was defined by average tolerated noise relative to speech levels (TNT) and by an average range of noise levels over a two-minute trial (excursion).

Characteristics of the quick repeat-recall test (Q-RRT).

Objective: To determine the reliability and validity of the Quick Repeat-Recall Test (Q-RRT).

Design: Within-subject repeated measures. Participants completed the Q-RRT at a speech level of 75 dB SPL in 2 noise configurations at signal-to-noise ratios of 5, 10, and 15 dB in a counterbalanced order, along with the full-RRT.

Measuring Objective and Subjective Intelligibility Using Speech Materials from the Tracking of Noise Tolerance (TNT) Test.

Background:  The results of tests measuring objective speech intelligibility are similar to those measuring subjective speech intelligibility using speech materials with minimal context. It is unclear if such is the case with contextual materials.

Purpose:  This article compares objective and subjective intelligibility difference (OSID) between normal hearing (NH) and hearing impaired (HI) listeners in the unaided and aided modes using speech materials adapted from the Tracking of Noise Tolerance (TNT) test.

Performance of older normal-hearing listeners on the tracking of noise tolerance (TNT) test.

Objective: To gather preliminary reference data on older normal-hearing (NH) adults for the refined Tracking of Noise Tolerance (TNT) test.

Design: Within-subject repeated measures. Participants were tested on the TNT in the sound-field and under headphones.

Left Lateralization of the Cortical Auditory-Evoked Potential Reflects Aided Processing and Speech-in-Noise Performance of Older Listeners With a Hearing Loss.

Objectives: We analyzed the lateralization of the cortical auditory-evoked potential recorded previously from aided hearing-impaired listeners as part of a study on noise-mitigating hearing aid technologies. Specifically, we asked whether the degree of leftward lateralization in the magnitudes and latencies of these components was reduced by noise and, conversely, enhanced/restored by hearing aid technology. We further explored if individual differences in lateralization could predict speech-in-noise abilities in listeners when tested in the aided mode.

Measuring the effect of adaptive directionality and split processing on noise acceptance at multiple input levels.

Objective: This study used the multi-level Tracking of Noise Tolerance (TNT) test to compare Augmented Focus (AF) or split processing over non-AF processing with adaptive directionality (non-AF-dirm) and with an omnidirectional microphone (non-AF-omni).

Design: This was a single-blind, within-subject repeated measures design.

Study Sample: Nineteen listeners with a mild-to-moderate hearing loss.

Use of Emotional and Neutral Speech in Evaluating Compression Speeds.

Background: Emotional speech differs from neutral speech in its envelope characteristics. Use of emotional speech materials may be more sensitive for evaluating signal processing algorithms that affect the temporal envelope.

Purpose: Subjective listener preference was compared between variable speed compression (VSC) and fast acting compression (FAC) amplitude compression algorithms using neutral and emotional speech.

Using the Repeat-Recall Test to Examine Factors Affecting Context Use.

Background: The effect of context on speech processing has been studied using different speech materials and response criteria. The Repeat-Recall Test (RRT) evaluates listener performance using high context (HC) and low context (LC) sentences; this may offer another platform for studying context use (CU).

Objective: This article aims to evaluate if the RRT may be used to study how different signal-to-noise ratios (SNRs), hearing aid technologies (directional microphone and noise reduction), and listener working memory capacities (WMCs) interact to affect CU on the different measures of the RRT.

Performance of normal-hearing listeners on the Repeat-Recall test in different noise configurations.

Objective: This study measured the performance of normal-hearing listeners on the Repeat-Recall Test (RRT) in two noise types (2-talker babble [2TBN] and continuous speech-shaped noise [SSN]) by two noise azimuths (0° and 180°) configurations at signal-to-noise ratios (SNRs) of 0, 5, 10, and 15 dB and quiet.

Design: Within-subject repeated measures.

Study Sample: Twenty-one listeners with normal hearing who also passed cognitive screening were tested in the sound-field with the speech stimulus presented from 0° at 75 dB SPL in 4 noise configurations.

Effects of Directional Microphone and Noise Reduction on Subcortical and Cortical Auditory-Evoked Potentials in Older Listeners With Hearing Loss.

Objectives: Understanding how signal processing influences neural activity in the brain with hearing loss is relevant to the design and evaluation of features intended to alleviate speech-in-noise deficits faced by many hearing aid wearers. Here, we examine whether hearing aid processing schemes that are designed to improve speech-in-noise intelligibility (i.e.

An Integrative Evaluation of the Efficacy of a Directional Microphone and Noise-Reduction Algorithm under Realistic Signal-to-Noise Ratios.

Background: Many studies on the efficacy of directional microphones (DIRMs) and noise-reduction (NR) algorithms were not conducted under realistic signal-to-noise ratio (SNR) conditions. A Repeat-Recall Test (RRT) was developed previously to partially address this issue.

Purpose: This study evaluated whether the RRT could provide a more comprehensive understanding of the efficacy of a DIRM and NR algorithm under realistic SNRs.

Tracking of Noise Tolerance to Predict Hearing Aid Satisfaction in Loud Noisy Environments.

Background: A method that tracked tolerable noise level (TNL) over time while maintaining subjective speech intelligibility was reported previously. Although this method was reliable and efficacious as a research tool, its clinical efficacy and predictive ability of real-life hearing aid satisfaction were not measured.

Purpose: The study evaluated an adaptive method to estimate TNL using slope and variance of tracked noise level as criteria in a clinical setting.

Simultaneously-evoked auditory potentials (SEAP): A new method for concurrent measurement of cortical and subcortical auditory-evoked activity.

Recent electrophysiological work has evinced a capacity for plasticity in subcortical auditory nuclei in human listeners. Similar plastic effects have been measured in cortically-generated auditory potentials but it is unclear how the two interact. Here we present Simultaneously-Evoked Auditory Potentials (SEAP), a method designed to concurrently elicit electrophysiological brain potentials from inferior colliculus, thalamus, and primary and secondary auditory cortices.

Cortical indices of sound localization mature monotonically in early infancy.

In human neonates, orienting behavior in response to an off-midline sound source disappears around the first postnatal month, only to re-emerge at ~4 months. To date, it is unclear whether sound localization processes continue to operate between postnatal months 1 and 3. Here, we used an event-related potential, reflecting change detection in the auditory cortices, to measure the cortical responses elicited by large (± 90° relative to midline), infrequent changes in sound source location in 2-, 5-, 8- and 13-month-old infants.