Venting Corrections Improve the Accuracy of Coupler-Based Simulated Real-Ear Verification for Use with Adult Hearing Aid Fittings.

BACKGROUND: Hearing aid responses can be verified with the Real-Ear Aided Response (REAR). Procedures for predicting the REAR from coupler-based verification exist, but have not incorporated corrections for venting, limiting their use and validity for vented and open fittings. A commercially available system for including venting effects in simulated real-ear measurement (S-REM) has recently been developed. PURPOSE: To evaluate the accuracy of a vent-corrected S-REM for predicting the REAR across test levels, for fittings with a wide range of coupling styles including modular domes. RESEARCH DESIGN: This was a within-subject comparison study using technical measures. Retrospective file review was used to obtain previously measured REARs from 104 fittings in 52 adults and three hearing aid styles. Prospective data collection was used to re-measure each fitting at three test levels using S-REM with and without venting corrections. Comparison of differences by frequency band was performed to assess the impact of the venting correction. RESULTS: The vent model reduced low-frequency error by up to 11 dB, and the effects were consistent with the expected effects of venting in hearing aid fitting: fittings with more open dome or tip styles had a larger improvement when the vent model was added. A larger sample of fittings was obtained for dome/sleeve couplings than for custom fittings. CONCLUSIONS: The vent-corrected S-REM system evaluated in this study provides improved fitting accuracy for dome or sleeve-fitted hearing aids for adults and supports the use of vented S-REM for open fittings. Further studies to examine a representative sample of custom tip or mold fittings, and fittings for children are future directions.

Differences in Force Levels, Word Recognition in Quiet, Sentence Reception Threshold in Noise, and Subjective Outcomes for a Bone-Anchored Hearing Device Programmed Using Manufacturer First-Fit, Aided Sound-Field Thresholds and Programmed to DSL-BCD Using a Skull Simulator.

BACKGROUND: Best practice guidelines for verifying fittings of bone-anchored hearing devices (BAHD) recommend using aided sound-field thresholds (ASFT), but express caution regarding the variables impacting obtaining valid and reliable ASFTs.1 Recently, a skull simulator was introduced to facilitate programming BAHD devices in force level (FL) to desired sensation level-bone conduction devices (skull simulator/DSL-BCD)2 3 targets in a hearing aid analyzer. Currently, no evidence is available reporting if differences in measured FL using the manufacturer first-fit (FF) and word recognition in quiet, sentence reception threshold in noise, and subjective outcomes are present for a BAHD programmed using ASFT versus programmed using skull simulator/DSL-BCD targets. PURPOSE: The aim of this study was to examine if significant differences were present in FL using the FF and word recognition in quiet at 50 and 65 decibel of sound pressure level (dB SPL), sentence reception threshold in noise and subjective outcomes using the abbreviated profile of hearing aid benefit (APHAB), and speech, spatial, and qualities of hearing (SSQ) between a BAHD fit using ASFT or skull simulator/DSL-BCD targets. RESEARCH DESIGN: A double-blind randomized crossover design with 15 adults having unilateral sensorineural hearing loss. All participants were successful users of the Cochlear America Baha 5. DATA COLLECTION AND ANALYSIS: Baha Power 5 devices were fit using FF, ASFT, and skull simulator/DSL-BCD targets. Order of the three fitting strategies was randomly assigned and counter-balanced. RESULTS: No significant differences were found for a BAHD device programmed using ASFT versus skull simulator/DSL-BCD targets for consonant-nucleus-consonant words in quiet at 50 or 65 dB SPL, sentence reception threshold in noise, the APHAB or SSQ. There were, however, significant differences, at primarily 500 to 2,000 Hz in measured FLs between the FF, ASFT, and skull simulator/DSL-BCD targets at 50 and 65 dB SPL. CONCLUSIONS: There were no significant differences in subject performance with two speech measures and subjective responses to two questionnaires for BAHD fittings using ASFT versus using skull simulator/DSL-BCD targets. Differences in FL between the three fitting strategies were present primarily at 500 to 2,000 Hz. Limitations of the study are highlighted along with situations where the skull simulator can play a significantly beneficial role when fitting BAHD devices.

Counseling During Real Ear Measurements: The Clients' Perspective.

BACKGROUND: When dispensing hearing aids, audiologists must follow validated fitting and verification procedures to ensure that the hearing aids are properly fitted to the client's hearing. Real ear measurements (REMs) are best practice for verifying hearing aids. Prior literature regarding REMs has mainly focused on the clinicians' perspective. PURPOSE: This study investigated informational counseling throughout REMs by gathering perspectives of first-time hearing aid users regarding the content and format of counseling. RESEARCH DESIGN: The study used an interpretive description approach with focus groups. STUDY SAMPLE: There were 16 adult participants (4 males, 12 females) who were first-time hearing aid users and who all had memory of REMs occurring during their own hearing aid verification. INTERVENTION: We investigated the addition of informational counseling during REM verification. DATA COLLECTION AND ANALYSIS: Four focus groups were conducted to elicit feedback on a demonstration of informational counseling during REM hearing aid verification. The data from the focus groups were transcribed verbatim and analyzed using qualitative content analysis. RESULTS: Analysis revealed positive aspects, negative aspects, and suggested changes in relation to the verbal and visual information presented during the REM verification demonstration. These data fell into two broad categories: the interaction and transaction of informational counseling. CONCLUSION: Most clients were interested in learning more about REMs if the information was accessible. Results provide recommendations for clinical audiologists and REM system manufacturers to make the information presented during informational counseling more client-friendly and individualized for client-centered care. To continue exploring this new inquiry, further experimental research is required to determine if there is any added value of incorporating informational counseling during REMs.

Fit-to-Targets and Aided Speech Intelligibility Index Values for Hearing Aids Fitted to the DSL v5-Adult Prescription.

BACKGROUND: Matching hearing aid output levels to prescribed targets is a component of preferred practice, yet recent normative data on appropriateness of fittings are lacking. Verification measures that assess closeness of fit-to-target include raw deviations from target, root-mean-squared-error (RMSE) deviations from target, and aided Speech Intelligibility Index (SII) values. Establishing normative ranges for these measures may help hearing professionals determine whether a patient's fit-to-targets and/or aided speech audibility is typical for his or her degree of hearing loss. PURPOSE: This article aims to characterize the range of fit-to-target and the range of aided SII associated with hearing aid fittings using the Desired Sensation Level version 5.0 (DSL v5-adult) prescription with adults, considering also hearing aid style, venting, and audiometric characteristics. RESEARCH DESIGN: A descriptive and correlational study of data collected from a retrospective chart review. RESULTS: Hearing aid fittings to 281 ears were compiled. The four-frequency average deviation from target (RMSE) was within ± 5 dB of target in 77% of fittings for mid-level speech. Deviation from targets increased with hearing loss, particularly when the loss is greater than 85 dB hearing level or if the loss was steeply sloping. Venting increased the deviation from targets in the low frequencies. Aided SII values strongly correlated with the participants' hearing thresholds. Clinical ranges for RMSE and aided SII were developed for characterization of fitting outcomes. CONCLUSION: Fitting to DSL v5-adult targets was observed within ± 5 dB absolute deviation, or within 5 dB RMSE, on average for typical adult hearing aid fittings. Confidence intervals for deviation from target and aided SII are proposed.

Evaluation of the Repeatability and Accuracy of the Wideband Real-Ear-to-Coupler Difference.

BACKGROUND: The real-ear-to-coupler difference (RECD) is an ANSI standardized method for estimating ear canal sound pressure level (SPL) thresholds and assisting in the prediction of real-ear aided responses. It measures the difference in dB between the SPL produced in the ear canal and the SPL produced in an HA-1 2-cc coupler by the same sound source. Recent evidence demonstrates that extended high-frequency bandwidth, beyond the hearing aid bandwidth typically measured, is capable of providing additional clinical benefit. The industry has, in turn, moved toward developing hearing aids and verification equipment capable of producing and measuring extended high-frequency audible output. As a result, a revised RECD procedure conducted using a smaller, 0.4-cc coupler, known as the wideband-RECD (wRECD), has been introduced to facilitate extended high-frequency coupler-based measurements up to 12.5 kHz. PURPOSE: This study aimed to (1) compare test-retest repeatability between the RECD and wRECD and (2) measure absolute agreement between the RECD and wRECD when both are referenced to a common coupler. RESEARCH DESIGN: RECDs and wRECDs were measured bilaterally in adult ears by calculating the dB difference in SPL between the ear canal and coupler responses. Real-ear probe microphone measures were completed twice per ear per participant for both foam-tip and customized earmold couplings using the Audioscan Verifit 1 and Verifit 2 fitting systems, followed by measurements in the respective couplers. STUDY SAMPLE: Twenty-one adults (mean age = 67 yr, range = 19-78) with typical aural anatomy (as determined by measures of impedance and otoscopy) participated in this study, leading to a sample size of 42 ears. DATA COLLECTION AND ANALYSIS: Repeatability within RECD and wRECD was assessed for each coupling configuration using a repeated-measures analysis of variance (ANOVA) with test-retest and frequency as within-participants factors. Repeatability between the RECD and wRECD was assessed within each configuration using a repeated-measures ANOVA with test-retest, frequency, and coupler type as within-participants factors. Agreement between the RECD and wRECD was assessed for each coupling configuration using a repeated-measures ANOVA with RECD value, coupler type, and frequency as within-participants factors. Post hoc comparisons with Bonferroni corrections were used when appropriate to locate the frequencies at which differences occurred. A 3-dB criterion was defined to locate differences of clinical significance. RESULTS: Average absolute test-retest differences were within ±3 dB within each coupler and coupling configuration, and between the RECD and wRECD. The RECD and wRECD were in absolute agreement following HA-1-referenced transforms, with most frequencies agreeing within ±1 dB, except at 0.2 kHz for the earmold, and 0.2-0.25 kHz for the foam tip, where the average RECD exceeded the average wRECD by slightly >3 dB. CONCLUSIONS: Test-retest repeatability of the RECD (up to 8 kHz) and wRECD (up to 12.5 kHz) is acceptable and similar to previously reported data. The RECD and wRECD are referenced to different couplers, but can be rendered comparable with a simple transform, producing values that are in accordance with the ANSI S3.46-2013 standard.

Clinical protocols for hearing instrument fitting in the Desired Sensation Level method.

A discussion of the protocols used particularly in the clinical application of the Desired Sensation Level (DSL) Method is presented in this chapter. In the first section, the measurement and application of acoustic transforms is described in terms of their importance in the assessment phase of the amplification fitting process. Specifically, the implications of individual ear canal acoustics and their impact on accurately defining hearing thresholds are discussed. Detailed information about the statistical strength of the real-ear-to-coupler difference (RECD) measurement and how to obtain the measure in young infants is also provided. In addition, the findings of a study that examined the relationship between behavioral and electrophysiologic thresholds in real-ear SPL is described. The second section presents information related to the electroacoustic verification of hearing instruments. The RECD is discussed in relation to its application in simulated measurements of real-ear hearing instrument performance. In particular, the effects of the transducer and coupling method during the RECD measurement are described in terms of their impact on verification measures. The topics of insertion gain, test signals, and venting are also considered. The third section presents three summary tables that outline the hearing instrument fitting process for infants, children, and adults. Overall, this chapter provides both clinical and scientific information about procedures used in the assessment and verification stages of the DSL Method.

The Desired Sensation Level multistage input/output algorithm.

The Desired Sensation Level (DSL) Method was revised to support hearing instrument fitting for infants, young children, and adults who use modern hearing instrument technologies, including multichannel compression, expansion, and multimemory capability. The aims of this revision are to maintain aspects of the previous versions of the DSL Method that have been supported by research, while extending the method to account for adult-child differences in preference and listening requirements. The goals of this version (5.0) include avoiding loudness discomfort, selecting a frequency response that meets audibility requirements, choosing compression characteristics that appropriately match technology to the user's needs, and accommodating the overall prescription to meet individual needs for use in various listening environments. This review summarizes the status of research on the use of the DSL Method with pediatric and adult populations and presents a series of revisions that have been made during the generation of DSL v5.0. This article concludes with case examples that illustrate key differences between the DSL v4.1 and DSL v5.0 prescriptions.