Hearing Loss
Conditions
Brief summary
The objective of this study protocol is to determine the efficacy of using aided measures of spectral resolution to set the dynamic range of hearing with hearing-aid amplification. Measures of spectral resolution will be obtained, as will measures of speech recognition.
Detailed description
Adults with hearing loss are more vulnerable to interference from background noise than adults with normal hearing. Despite the fact that the ability to extract speech information imbedded in background noise requires decoding differences in level across frequency (spectral information), few studies have addressed the extent to which spectral information can be provided to listeners with hearing loss. This fundamental gap in our knowledge prevents society from effectively addressing the systemic effects of hearing loss on communication, income, and ability to socialize with others. This work is a new application of established methods of characterizing spectral resolution to that of the most common device for rehabilitation of hearing loss, hearing-aid amplification. Because hearing aids do not require premarket approval, FDA oversight is not applicable to this clinical trial. The experiments will examine the degree to which access to spectral information can be restored to adults with hearing loss and the feasibility of utilizing this information to decrease interference from background noise. Aim 1 will delineate the impact of hearing-aid amplification on spectral decoding. Technology options that must be set by the clinician or hearing-aid manufacturer will be examined, including the frequency-specific gain, compressor speed, and number of compression channels. The proposed experiments will test the hypothesis that restoration of the lost dynamic range of hearing can support the encoding of spectral information. It is also hypothesized that the combination of technology options that best restore access to spectral information will differ across individuals and that these differences across individuals can be partially accounted for by an estimate of outer hair cell function. Aim 2 will determine the extent to which restoring access to spectral information supports speech recognition in background noise, under the guiding hypothesis that improving spectral resolution increases speech understanding. If it can be demonstrated that measures of spectral resolution with the provision of amplification are useful at delineating those who stand to benefit from different technology options, the knowledge gained could then be applied to the clinic to allow for clinicians to more successfully choose among different rehabilitation options.
Interventions
DEVICEHearing Aid
Hearing Aid
Sponsors
National Institute on Deafness and Other Communication Disorders (NIDCD)
University of Nebraska Lincoln
Study design
Allocation
NON_RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
40 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* normal tympanograms (peak admittance of ≥ 0.2 mmhos, -200 to 50); Hearing thresholds for normal hearing group less than or equal to 20 decibels in hearing level (dB HL) from .25 to 8 kHz. Pure-tone average (2, 4 & 6 kHz) hearing thresholds for participants with hearing loss of 30 - 65 dB HL.
Exclusion criteria
* cognitive impairment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Spectral Resolution | Each test was approximately 10 minutes and was completed after each experimental manipulation | Measure of spectral resolution (Q10) obtained from the fast psychophysical tuning curve test. For this study, Q10 was computed as the target frequency divided by the bandwidth of the tuning curve (10 dB above the threshold at the tip of the tuning curve test). Higher numbers on this scale indicate sharper (better) tuning. The lower limit for this scale is 0 and there is no upper limit. |
| Speech Recognition | Each test was approximately 10 minutes and was completed after each experimental manipulation | measure of spatial release from masking (dB) for a masker presented at 70 dB SPL. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Working Memory | Each test was approximately 30 minutes and was completed only once per subject. | Measure of working memory (correctly repeated words from the reading span test). The minimum (poorer) and maximum (better) values are 0 and 57, respectively. |
Countries
United States
Participant flow
Pre-assignment details
Participants completed a questionnaire about their medical and developmental history and educational level. Participants cognitive ability assessed using the Montreal Cognitive Assessment Basic (MOCA-B). Each subject underwent a routine audiological examination, including audiometric testing and tympanometry. Due to not qualifying on basis of inclusion or exclusion criteria (age, degree of hearing loss, or tympanometric findings), 85 participants were excluded before assignment to groups.
Participants by arm
| Arm | Count |
|---|---|
| Normal Hearing Group of participants with normal hearing that serve as a reference group. | 25 |
| Hearing Aid Group of participants with sensorineural hearing loss who were tested under conditions with hearing aid amplification. | 85 |
| Total | 110 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Did Not Condition To Experiment | 7 | 2 |
| Overall Study | Experimenter Error | 1 | 1 |
| Overall Study | Withdrawal by Subject | 3 | 0 |
Baseline characteristics
| Characteristic | Normal Hearing | Hearing Aid | Total |
|---|---|---|---|
| Age, Continuous | 66 years | 70 years | 69 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 23 Participants | 79 Participants | 102 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 2 Participants | 6 Participants | 8 Participants |
| Montreal Cognitive Assessment Basic (MOCA-B) | 26 scores on a scale | 26 scores on a scale | 26 scores on a scale |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 2 Participants | 0 Participants | 2 Participants |
| Race (NIH/OMB) White | 23 Participants | 84 Participants | 107 Participants |
| Region of Enrollment United States | 25 participants | 85 participants | 110 participants |
| Sex: Female, Male Female | 20 Participants | 47 Participants | 67 Participants |
| Sex: Female, Male Male | 5 Participants | 38 Participants | 43 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 0 | 0 / 0 |
| other Total, other adverse events | 0 / 0 | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 | 0 / 0 |
Outcome results
Primary
Spectral Resolution
Measure of spectral resolution (Q10) obtained from the fast psychophysical tuning curve test. For this study, Q10 was computed as the target frequency divided by the bandwidth of the tuning curve (10 dB above the threshold at the tip of the tuning curve test). Higher numbers on this scale indicate sharper (better) tuning. The lower limit for this scale is 0 and there is no upper limit.
Time frame: Each test was approximately 10 minutes and was completed after each experimental manipulation
Population: Consisted of varying conditions and number of participants per condition, including three different compression speeds (instant, fast, slow), three different number of compression channels (4, 8, 16) and two different amplification conditions (unaided, aided).
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Hearing Aid Group | Spectral Resolution | Aided | 3.2 units on a scale | Standard Deviation 1.1 |
| Hearing Aid Group | Spectral Resolution | Fast | 3.3 units on a scale | Standard Deviation 1.9 |
| Hearing Aid Group | Spectral Resolution | Slow | 3.2 units on a scale | Standard Deviation 1.6 |
| Hearing Aid Group | Spectral Resolution | 4 Channels | 2.8 units on a scale | Standard Deviation 1.2 |
| Hearing Aid Group | Spectral Resolution | 8 Channels | 2.5 units on a scale | Standard Deviation 1.7 |
| Hearing Aid Group | Spectral Resolution | 16 Channels | 3.5 units on a scale | Standard Deviation 1.1 |
| Hearing Aid Group | Spectral Resolution | Unaided | 2.7 units on a scale | Standard Deviation 1.7 |
| Hearing Aid Group | Spectral Resolution | Instant | 3.5 units on a scale | Standard Deviation 2.2 |
| Normal Hearing | Spectral Resolution | Unaided | 3.9 units on a scale | Standard Deviation 2 |
Comparison: This analysis examined Q10 for those participants who completed the compression speed experiment (instant, fast, slow).p-value: 0.774ANOVA
Comparison: This analysis examined Q10 for those participants who completed the compression channel conditions (4, 8, 16).p-value: <0.001ANOVA
Comparison: This analysis compared Q10 for those participants who completed the unaided and aided conditions.p-value: 0.167ANOVA
Primary
Speech Recognition
measure of spatial release from masking (dB) for a masker presented at 70 dB SPL.
Time frame: Each test was approximately 10 minutes and was completed after each experimental manipulation
Population: Participants with normal hearing were only tested unaided. Participants with hearing loss were tested unaided, 4 channels with fast compression, and 16 channels with fast compression. Fast compression with 4 and 16 channels were assessed to assess the potential role of changes in spectral resolution to changes in speech recognition between these two conditions.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Hearing Aid Group | Speech Recognition | unaided | 6.6 dB | Standard Deviation 5.1 |
| Normal Hearing | Speech Recognition | unaided | 4.5 dB | Standard Deviation 1.9 |
| Normal Hearing | Speech Recognition | 4 channels | 4.0 dB | Standard Deviation 3.2 |
| Normal Hearing | Speech Recognition | 16 channels | 3.7 dB | Standard Deviation 2.8 |
Comparison: Statistical analysis of number of compression channels (unaided, 4 channel, 16 channels)p-value: 0.741ANOVA
Comparison: Spatial Release from Masking, unaided.p-value: 0.062t-test, 1 sided
Secondary
Working Memory
Measure of working memory (correctly repeated words from the reading span test). The minimum (poorer) and maximum (better) values are 0 and 57, respectively.
Time frame: Each test was approximately 30 minutes and was completed only once per subject.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Hearing Aid Group | Working Memory | 23.6 score on a scale | Standard Deviation 6.8 |
| Normal Hearing | Working Memory | 20.1 score on a scale | Standard Deviation 7.4 |
Comparison: Linear regression of score for the reading span (independent variable) to Q10 (dependent variable, 16 channel compression condition) for the participants who completed the compression channel experiment.p-value: 0.805Regression, Linear