Perceptual Benefits of Extended Bandwidth Hearing Aids With Children: A Within-Subject Design Using Clinically Available Hearing Aids

Validity and reliability of integrated pressure level real-ear-to-coupler difference measurements

OBJECTIVES

(1) To validate the measurement of foam-tip real-ear-to-coupler differences (wRECD) using an integrated pressure level (IPL) method and (2) to compare the reliability of this method to SPL-based measurement of the wRECD.

DESIGN

SPL-based wRECD and the proposed IPL wRECD measurement were completed bilaterally. Test-retest reliability of IPL wRECD was determined with full re-insertion into the ear canal and compared to published SPL wRECD test-retest data.

STUDY SAMPLE

22 adults with normal hearing and middle ear status were recruited.

RESULTS

Differences between SPL-based wRECD and IPL wRECD measurements were within 1.51 dB on average below 5000 Hz. At and above 5000 Hz, IPL wRECD exceeded SPL wRECDs by 6.11 dB on average. The average test-retest difference for IPL wRECD across all assessed frequencies was 0.75 dB with the greatest improvements in reliability found below 750 Hz and above 3000 Hz.

CONCLUSIONS

IPL wRECD yielded improved estimates compared to SPL wRECD in high frequencies, where standing-wave interference is present. Independence from standing wave interference resulted in increased wRECD values above 4000 Hz using the IPL measurement paradigm. IPL wRECD is more reliable than SPL wRECD, does not require precise probe-microphone placement, and provides a wider valid wRECD bandwidth than SPL-based measurement.

Development of amplitude modulation, voice onset time, and consonant identification in noise and reverberation

Children's speech understanding is vulnerable to indoor noise and reverberation: e.g., from classrooms. It is unknown how they develop the ability to use temporal acoustic cues, specifically amplitude modulation (AM) and voice onset time (VOT), which are important for perceiving distorted speech. Through three experiments, we investigated the typical development of AM depth detection in vowels (experiment I), categorical perception of VOT (experiment II), and consonant identification (experiment III) in quiet and in speech-shaped noise (SSN) and mild reverberation in 6- to 14-year-old children. Our findings suggested that AM depth detection using a naturally produced vowel at the rate of the fundamental frequency was particularly difficult for children and with acoustic distortions. While the VOT cue salience was monotonically attenuated with increasing signal-to-noise ratio of SSN, its utility for consonant discrimination was completely removed even under mild reverberation. The reverberant energy decay in distorting critical temporal cues provided further evidence that may explain the error patterns observed in consonant identification. By 11-14 years of age, children approached adult-like performance in consonant discrimination and identification under adverse acoustics, emphasizing the need for good acoustics for younger children as they develop auditory skills to process distorted speech in everyday listening environments.

A comparison of automated verification using paediatric hearing aids

OBJECTIVE

Best-practice guidelines recommend the use of hearing aid verification in children; however, this is not always performed. Automated hearing aid verification has been reported to be more accurate and efficient than manual verification in adults, but it is not known if this transfers to the paediatric population.

DESIGN

A within-group design compared manual and automated hearing aid verification on four measures; fitting accuracy, prescription targets, completion time, and the speech intelligibility index.

SAMPLE

Twenty paediatric patient hearing aid profiles (M = 8.25 years) with unilateral or bilateral hearing aids.

RESULTS

A Wilcoxon-signed rank test indicated manual verification achieved a significantly closer match to target at 0.5 kHz, by an average of 1 dB. There were no significant differences at any other frequency. Across 80 comparisons (four frequencies measured in 20 listeners), 82.5% of automated verifications were identical to, or within 1 dB of, manual verifications. A paired-samples t-test confirmed automated verification to be an average of 91.9 seconds faster than manual verification.

CONCLUSION

Automated verification was able to provide an accurate match to target within recommended tolerances for hearing aid fittings and was significantly quicker than manual verification. These data suggest that automated verification of hearing aids could play a role in paediatric audiological management.

Predicting wideband real-ear-to-coupler differences in children using wideband acoustic immittance

Individual differences in ear-canal acoustics introduce variability into hearing aid output that can affect speech audibility. Measuring ear-canal acoustics in young children can be challenging, and relying on normative real-ear-to-coupler difference (RECD) transforms can lead to large fitting errors. Acoustic immittance measures characterize the impedance of the ear and are more easily measured than RECD. Using 226 Hz tympanometry to predict the RECD is more accurate than using age-based average RECD values. The current study sought to determine whether wideband acoustic immittance measurements could improve predictions of wideband real-ear-to-coupler difference (wRECD). 150 children ages 2-10 years with intact tympanic membranes underwent wRECD and wideband acoustic immittance measures in each ear. Three models were constructed to predict each child's measured wRECD: the age-based average wRECD, 226 Hz admittance wRECD, and wideband absorbance wRECD. The average age-based wRECD model predicted the child's measured wRECD within 3 dB in 62% of cases, but both the 226 Hz admittance and wideband absorbance wRECD were within 3 dB in 90% of cases. Using individual 226 Hz or wideband absorbance to predict wRECD improved the accuracy and precision of transforms used for pediatric hearing aid fitting.

Predicting Hearing aid Benefit Using Speech-Evoked Envelope Following Responses in Children With Hearing Loss

Electroencephalography could serve as an objective tool to evaluate hearing aid benefit in infants who are developmentally unable to participate in hearing tests. We investigated whether speech-evoked envelope following responses (EFRs), a type of electroencephalography-based measure, could predict improved audibility with the use of a hearing aid in children with mild-to-severe permanent, mainly sensorineural, hearing loss. In 18 children, EFRs were elicited by six male-spoken band-limited phonemic stimuli--the first formants of /u/ and /i/, the second and higher formants of /u/ and /i/, and the fricatives /s/ and /∫/--presented together as /su∫i/. EFRs were recorded between the vertex and nape, when /su∫i/ was presented at 55, 65, and 75 dB SPL using insert earphones in unaided conditions and individually fit hearing aids in aided conditions. EFR amplitude and detectability improved with the use of a hearing aid, and the degree of improvement in EFR amplitude was dependent on the extent of change in behavioral thresholds between unaided and aided conditions. EFR detectability was primarily influenced by audibility; higher sensation level stimuli had an increased probability of detection. Overall EFR sensitivity in predicting audibility was significantly higher in aided (82.1%) than unaided conditions (66.5%) and did not vary as a function of stimulus or frequency. EFR specificity in ascertaining inaudibility was 90.8%. Aided improvement in EFR detectability was a significant predictor of hearing aid-facilitated change in speech discrimination accuracy. Results suggest that speech-evoked EFRs could be a useful objective tool in predicting hearing aid benefit in children with hearing loss.

Clinical Practice Patterns With Pediatric Loudness Perception Measures

PURPOSE

Obtaining a patient's loudness discomfort level (LDL) can assist the audiologist in defining their dynamic range so that the hearing device fitting can ensure that low-level sounds are audible, average-level sounds are comfortable, and more intense sounds are loud but not too loud. A 2016 survey showed that 67.5% of 350 pediatric audiologist reported to never or rarely measure LDLs with pediatric patients. The purpose of this study was to identify factors influencing this previously reported limited use of LDL measures.

METHOD

Sixty-two pediatric audiologists in the United States were surveyed using a questionnaire that sought to improve our understanding of the (non)use of loudness perception measures with pediatric patients and to assess familiarity with various loudness perception measurements. In addition, the questionnaire gathered information about the needs of pediatric audiologists in relation to LDL measures.

RESULTS

Audiologist report being largely unfamiliar with methods of assessing loudness perception in children, with categorical loudness scaling being the method with which they are most familiar. In addition, audiologists reported being more willing and able to measure LDLs in older compared to younger pediatric patients. Limited use of pediatric loudness perception measures appears to be driven by a lack of familiarity with measurement methods and the belief that loudness perception measures may not be useful for clinical practice.

CONCLUSIONS

Findings highlight audiologists' need for further information regarding the relevance of loudness perception measurements with pediatric patients and the need for easy-to-implement LDL measurement procedures for pediatric patients of all ages.

Premium versus entry-level hearing aids: using group concept mapping to investigate the drivers of preference

OBJECTIVES

To investigate the difference in outcome measures and drivers of user preference between premium and entry-level hearing aids using group concept mapping.

DESIGN

A single-blind crossover trial was conducted. Aided behavioural outcomes measured were loudness rating, speech/consonant recognition, and speech quality. Preference between hearing aids was measured with a 7-point Likert scale. Group concept mapping was utilised to investigate preference results. Participants generated statements based on what influenced their preferences. These were sorted into categories with underlying themes. Participants rated each statement on a 5-point Likert scale of importance.

STUDY SAMPLE

Twenty-three adult participants (mean: 62.4 years; range: 24-78) with mild to moderately severe bilateral SNHL (PTA_{500-4000 Hz} > 20 dB HL).

RESULTS

A total of 83 unique statements and nine distinct clusters, with underlying themes driving preference, were generated. Clusters that differed significantly in importance between entry-level and premium hearing aid choosers were: Having access to smartphone application-based user-controlled settings, the ability to stream calls and music, and convenience features such as accessory compatibility.

CONCLUSION

This study has identified non-signal-processing factors which significantly influenced preference for a premium hearing aid over an entry-level hearing aid, indicating the importance of these features as drivers of user preference.

The use of ecological momentary assessment to evaluate real-world aided outcomes with children

BACKGROUND

Ecological momentary assessment (EMA) methods allow for real-time, real-world survey data collection. Studies with adults have reported EMA as a feasible and valid tool in the measurement of real-world listening experience. Research is needed to investigate the use of EMA with children who wear hearing aids.

OBJECTIVES

This study explored the implementation of EMA with children using a single-blinded repeated measures design to evaluate real-world aided outcome.

METHODS

Twenty-nine children, aged 7-17, used manual program switching to access hearing aid programs, fitted according to Desired Sensation Level (DSL) version 5.0 child quiet and noise prescriptive targets. Aided outcome was measured using participant-triggered twice-daily EMA entries, across listening situations and hearing dimensions.

RESULTS

Adherence to the EMA protocol by the children was high (82.4% compliance rate). Speech loudness, understanding and preference results were found to relate to both the hearing aid program and the listening situation. Aided outcomes related to prescription-based noise management were found to be highest in noisy situations.

CONCLUSIONS

Mobile device-based EMA methods can be used to inform daily life listening experience with children. Prescription-based noise management was found to decrease perceived loudness in noisy, non-school environments; this should be evaluated in combination with hearing aid noise reductions features.

Characteristics of Speech-Evoked Envelope Following Responses in Infancy

Envelope following responses (EFRs) may be a useful tool for evaluating the audibility of speech sounds in infants. The present study aimed to evaluate the characteristics of speech-evoked EFRs in infants with normal hearing, relative to adults, and identify age-dependent changes in EFR characteristics during infancy. In 42 infants and 21 young adults, EFRs were elicited by the first (F1) and the second and higher formants (F2+) of the vowels /u/, /a/, and /i/, dominant in low and mid frequencies, respectively, and by amplitude-modulated fricatives /s/ and /∫/, dominant in high frequencies. In a subset of 20 infants, the in-ear stimulus level was adjusted to match that of an average adult ear (65 dB sound pressure level [SPL]). We found that (a) adult-infant differences in EFR amplitude, signal-to-noise ratio, and intertrial phase coherence were larger and spread across the frequency range when in-ear stimulus level was adjusted in infants, (b) adult-infant differences in EFR characteristics were the largest for low-frequency stimuli, (c) infants demonstrated adult-like phase coherence when they received a higher (i.e., unadjusted) stimulus level, and (d) EFR phase coherence and signal-to-noise ratio changed with age in the first year of life for a few F2+ vowel stimuli in a level-specific manner. Together, our findings reveal that development-related changes in EFRs during infancy likely vary by stimulus frequency, with low-frequency stimuli demonstrating the largest adult-infant differences. Consistent with previous research, our findings emphasize the significant role of stimulus level calibration methods while investigating developmental trends in EFRs.