Listener Performance with a Novel Hearing Aid Frequency Lowering Technique.

BACKGROUND: Sloping hearing loss imposes limits on audibility for high-frequency sounds in many hearing aid users. Signal processing algorithms that shift high-frequency sounds to lower frequencies have been introduced in hearing aids to address this challenge by improving audibility of high-frequency sounds. PURPOSE: This study examined speech perception performance, listening effort, and subjective sound quality ratings with conventional hearing aid processing and a new frequency-lowering signal processing strategy called frequency composition (FC) in adults and children. RESEARCH DESIGN: Participants wore the study hearing aids in two signal processing conditions (conventional processing versus FC) at an initial laboratory visit and subsequently at home during two approximately six-week long trials, with the order of conditions counterbalanced across individuals in a double-blind paradigm. STUDY SAMPLE: Children (N = 12, 7 females, mean age in years = 12.0, SD = 3.0) and adults (N = 12, 6 females, mean age in years = 56.2, SD = 17.6) with bilateral sensorineural hearing loss who were full-time hearing aid users. DATA COLLECTION AND ANALYSES: Individual performance with each type of processing was assessed using speech perception tasks, a measure of listening effort, and subjective sound quality surveys at an initial visit. At the conclusion of each subsequent at-home trial, participants were retested in the laboratory. Linear mixed effects analyses were completed for each outcome measure with signal processing condition, age group, visit (prehome versus posthome trial), and measures of aided audibility as predictors. RESULTS: Overall, there were few significant differences in speech perception, listening effort, or subjective sound quality between FC and conventional processing, effects of listener age, or longitudinal changes in performance. Listeners preferred FC to conventional processing on one of six subjective sound quality metrics. Better speech perception performance was consistently related to higher aided audibility. CONCLUSIONS: These results indicate that when high-frequency speech sounds are made audible with conventional processing, speech recognition ability and listening effort are similar between conventional processing and FC. Despite the lack of benefit to speech perception, some listeners still preferred FC, suggesting that qualitative measures should be considered when evaluating candidacy for this signal processing strategy.

Effects of Hand Placement Technique on the Video Head Impulse Test (vHIT) in Younger and Older Adults.

OBJECTIVE: To investigate the effects of hand placement techniques on the video head impulse test (vHIT) responses (i.e., gain, velocity) in older and younger adults and to determine intra-rater and inter-rater reliability of the horizontal vHIT. DESIGN: Descriptive, reliability study. SETTING: University research laboratory. SUBJECTS: Forty healthy adults grouped by age with negative history of current or previous vestibular diseases between the ages of 20 and 88 years (mean = 46.60, standard deviation 23.20). MAIN OUTCOME MEASURES: Three examiners each used two hand placement techniques (chin and head) to elicit the horizontal vHIT responses. Both the examiner and hand placement orders were counterbalanced to account for order and fatigue effects. The outcome measures of interest were vHIT gain and velocity. RESULTS: A two-way between-subject factorial analysis of variance revealed a significant main effect for hand placement technique and gain response. Mean values for vHIT gain were higher for head technique. Significant main effects were observed for the velocity response for hand placement technique and age group. Mean velocity values were higher for chin technique and lower velocities were observed in the older age group. Intra- and inter-rater reliability scores were consistent for gain values; however, poor to fair inter-rater reliability scores were observed for velocity values. CONCLUSION: It is suggested that clinical sites select one hand placement technique for the measure to provide consistency of protocol. Establishing clinical norms using the one selected method to verify reliability within and across clinicians is suggested before examination with a disordered population.