Auditory Training and Hearing Aid Satisfaction: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Auditory Training and Hearing Aid Satisfaction (NCT04230876), a non-randomized phase 1 study. The primary outcome is Change in Hearing Aid Satisfaction After Auditory Training.

2. Clinical Question

The study summary frames the research question around satisfaction with new hearing aids and daily use time. The registered primary outcome, however, is change in COSI satisfaction scores. Daily use time is not listed as the primary outcome in the record, and its status as an outcome measure is not specified in the information.

The summary also describes an interest in whether training is associated with higher satisfaction and longer daily use. Because the design is single-group and non-randomized, the registered question is most directly about change over time in the participants who received the training. The design information does not describe a control condition that would separate change associated with training from other possible explanations for change.

3. Trial Design

The study is listed as a Phase 1, non-randomized, single-group trial with single masking. The registry enrollment is 30. The sponsor is Washington University School of Medicine. The record lists the status as completed, with a start date of 2020-09-01 and a primary completion date of 2021-02-28.

The intervention is described as auditory brain training games and activities. The brief summary calls the training clEAR, and the primary-outcome description refers to participants using Amptify DTx. The registry record does not explain whether these names refer to the same program or how the training was delivered. The specific masking procedure and who was masked are not reported in the registry record.

A single-group design can describe measurements within participants over time, but it does not by itself provide a concurrent untreated comparison. Non-randomized allocation also means there is no randomized assignment described in the design. The record's own warning notes that the arms are not a like-for-like control comparison. Consequently, comparisons between groups, if any are presented elsewhere in the record, should not be treated as randomized treatment contrasts.

The primary outcome timeframe is stated as “Three weeks after hearing aid fitting and after completing the four week training protocol.” That wording gives a fitting-related time point and a training duration, but the precise sequence and timing of each assessment are not further explained. The record does not report the protocol, planned analysis details, eligibility criteria, or how participants were recruited.

The registry lists six outcome measures and six analyses. The names and results for all outcomes and analyses are not detailed in the information presented for this interpretation. A secondary outcome is change in percent words correct on speech perception measures after auditory training. The record does not report numerical outcome estimates in the material.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Change in Hearing Aid Satisfaction After Auditory Training, measured over Three weeks after hearing aid fitting and after completing the four week training protocol..

The primary endpoint is change in hearing-aid satisfaction after auditory training. It is measured with the Client Orientated Scale of Improvement (COSI), a subjective instrument based on improvement in goals defined by each participant. The record describes the scale relative to a baseline assessed before hearing-aid use.

For each goal, the response options range from Worse (-1) and No Difference (0), through Slightly Better (+1) and Better (+2), to Much Better (+3). Thus, positive scores indicate perceived improvement in the self-defined goal, zero indicates no improvement, and a negative score indicates that the goal became worse. The registry describes the endpoint as the difference between scores before and after use of Amptify DTx. It does not specify the subtraction order, so the direction of a reported change cannot be independently interpreted from the description alone.

A participant-defined measure is relevant to a question about satisfaction because it captures perceived change in goals that matter to the participant, rather than only performance on a standardized speech task. It is subjective by design, and the meaning of a score depends on the selected goals and the participant’s assessment. The record describes the outcome parameter as a mean and the dispersion measure as a standard deviation, but numerical estimates for the primary endpoint are not reported in the registry record.

The stated timeframe refers to assessment three weeks after hearing-aid fitting and after the four week training protocol. The exact assessment schedule is not further clarified.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean and standard deviation describe?

The registry identifies the primary outcome as a continuous measure analyzed using a mean, with standard deviation as the dispersion measure. In general, a mean gives a central summary of observed scores, while a standard deviation describes how spread out those scores are around the mean. Together they can describe the average change and the variability in participant-level changes. They do not, on their own, show how precisely the mean is estimated. Numerical values for the primary mean and standard deviation are not reported in the registry record information.

COSI responses use ordered categories from Worse (-1) to Much Better (+3), including No Difference (0), Slightly Better (+1), and Better (+2). The registry nevertheless specifies a mean as the outcome parameter. In general, summarizing ordered scores with a mean treats differences between adjacent score values as meaningful for the summary. That is a statistical convention, and it does not change the scale’s participant-reported nature. The record does not report additional analyses of the category distribution.

What would a confidence interval add?

In general, a confidence interval expresses uncertainty around an estimated effect under the assumptions of the statistical method used. A narrow interval indicates greater precision than a wide interval, while the interval’s position helps readers understand which values are compatible with the data and method. The registry information does not report a confidence interval for the primary outcome. Without an estimate and its uncertainty, the result’s precision cannot be evaluated.

A p-value, when reported, addresses how compatible the observed data are with a specified null model under the assumptions of the test. It does not measure the size or practical importance of an effect. No primary-outcome p-value or test procedure is reported in the registry record information. The analysis plan and inferential procedure are not reported in the registry record.

How does the study design shape the comparison?

The listed model is single-group and allocation is non-randomized. In general, a before-and-after analysis in one group estimates change over time among those measured; it does not supply the counterfactual outcome that would have occurred without intervention. A randomized control group can support a different kind of comparison, but one is not described in this design. The registry itself flags that the arms are not a like-for-like control comparison.

Single masking is listed, but the record does not identify who was masked or what procedures were used. In general, masking can reduce the influence of expectations or knowledge of treatment assignment on some aspects of measurement or assessment. Without the operational details, the potential role of masking in this study cannot be evaluated.

Why can over-dispersion matter?

In general, over-dispersion means that observed variability is greater than a statistical model expects. If a model assumes less variability than is present, standard errors may be too small and uncertainty may be understated. The primary endpoint is described as a continuous measure with a standard deviation; the record information does not report a model or an over-dispersion assessment. This concept is therefore general context, not a claim that over-dispersion occurred in this study.

What do planning illustrations mean?

The registry describes sample-size calculations as planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says that the effect to detect is a stated fraction of the observed effect. These calculations are illustrations for planning, not observed power, and they do not describe the trial’s own design justification. The registry record does not report the trial’s sample-size justification. Because the design is single-group, the illustration’s equal-allocation assumption should not be mistaken for the design that is listed for the study.

In general, a sample-size calculation depends on assumptions about the effect to detect, outcome variability, allocation, and the chosen error rate. Changing these assumptions changes the planning estimate. Such calculations do not show that a study had a particular probability of finding an effect after it was completed. The numerical planning results are not restated.

What analysis details are absent?

The registry lists six outcome measures and six analyses, but the analysis procedures, model specifications, handling of repeated measurements, covariate adjustment, and analysis population are not reported in the registry record information. The record also does not state whether analyses were prespecified or whether any interim analyses took place. These details matter because they define which observations contribute to an estimate and how uncertainty is calculated.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Amptify First", "Amptify Second")
n   <- c(14, 14)
m   <- c(1.9, 1.7)
sp  <- c(0.7, 0.9)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Amptify First  14  1.900  0.700  1.496  2.304
CARM  Amptify Second  14  1.700  0.900  1.180  2.220

11. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures and six analyses. The analysis plan does not report how the study handled multiple outcomes or multiple statistical tests. In general, examining several outcomes can increase the chance of at least one apparently notable result if each is considered separately. Methods such as prespecifying a primary outcome or adjusting for multiple comparisons can address different aspects of this issue, but the registry record does not report whether such methods were planned or used. The primary outcome is identified as change in hearing-aid satisfaction.

Missing-data counts, reasons for missingness, and methods for handling missing observations are not reported in the registry record. The number of participants contributing to the primary analysis is also not reported in the information. In general, missingness can affect both the precision and interpretation of an estimate, particularly if the availability of measurements is related to participants’ outcomes. Without the extent and handling of missing data, that potential cannot be assessed for this study.

The record information does not define an intention-to-treat, per-protocol, or other analysis population. It does not explain whether all enrolled participants were included in each analysis or how withdrawals, if any, were handled. Those omissions limit reproducibility and make it difficult to determine which participants the reported estimates would represent.

Although the registry identifies a primary outcome, no statistical analysis plan or multiplicity procedure is reported in the registry record. The status of secondary analyses as confirmatory or exploratory is not specified.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The serious-adverse-event record lists two labels: “Amptify First” and “Amptify Second.” For each label, the number at risk for serious adverse events is 15 and the number with a serious adverse event is 0. The record also lists 0 deaths for each label. Other adverse events are recorded as 0 for each label.

These are counts as recorded, not estimates of comparative risk. The study design is described as non-randomized and single-group, and the registry warning says the arms are not a like-for-like control comparison. The relationship between the two adverse-event labels and the single-group design is not explained in the registry record. A comparison between the labels therefore should not be interpreted as a randomized safety contrast.

Zero recorded events does not establish that an event is impossible or that all potential safety concerns were absent. In general, the interpretation of event counts depends on how events were defined, collected, and followed. Those procedures and the completeness of event reporting are not reported in the registry record information. These safety entries should be kept separate from the primary satisfaction outcome and from claims about training effects.

13. What the Result Does, and Does Not, Mean

The registry record identifies a study of auditory brain training among older adults receiving new hearing aids, with change in COSI satisfaction as the primary outcome. Its design is listed as non-randomized and single-group. Those details define the kind of question the study can address: whether scores changed among participants measured around the training period, rather than whether training outperformed a concurrent randomized control condition.

The record information does not include a numerical primary-outcome result, uncertainty interval, or test result. It is therefore not possible to state how much satisfaction changed, in which direction, or with what precision. The study summary’s interest in daily use time does not establish that daily use changed; a numerical result for that outcome is not reported in the registry record information.

Even if a before-and-after change is reported elsewhere in the registry, a single-group design cannot by itself attribute that change to auditory training. General alternative explanations include adjustment to hearing aids, time, repeat measurement, and other influences occurring during the study. The record does not report design features that would isolate the effect of training from these possibilities.

The COSI reflects participants’ ratings of improvement in goals they define for themselves. It can therefore represent perceived change in those goals, but it is not a direct measure of speech recognition, daily use, or a clinical diagnosis. The listed secondary outcome, change in percent words correct on speech-perception measures, addresses a different construct.

The registry’s serious-adverse-event entries show zero events and zero deaths for each listed label, but do not establish the completeness of safety surveillance or permit a controlled safety comparison. Overall, the record describes the research question and some design and outcome definitions; the results and analysis details needed to judge the magnitude, precision, and attribution of any change are not reported in the registry record information.

14. Why This Trial Matters Statistically

This study illustrates why the design and the outcome definition must be read together. The primary measure is a participant-reported change in goals selected by each participant. That focus is relevant to satisfaction, but it differs from standardized speech-perception performance and from daily hearing-aid use. Keeping those constructs separate avoids treating a result in one as evidence about another.

The non-randomized, single-group design also sets an important boundary on interpretation. A within-participant change can be informative about what happened over the measurement period, but without a suitable concurrent comparator it does not isolate the contribution of training. This distinction applies even when the outcome is directly relevant to participants.

The record’s use of different program names—clEAR in the study summary and Amptify DTx in the primary-outcome description—creates a reporting detail that readers may want clarified. The relationship between those names is not reported in the registry record. Likewise, the adverse-event labels “Amptify First” and “Amptify Second” are not reconciled with the listed single-group model.

Finally, the absence of numerical primary results and analysis details limits assessment of both effect size and precision. A clearly defined endpoint is necessary for interpretation, but it is not enough: readers also need the estimate, uncertainty, analytic population, and missing-data information. These features determine what the reported evidence can support.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record information does not report numerical results for the primary endpoint. Without the mean change, standard deviation, and uncertainty estimate, the magnitude, direction, and precision of the outcome cannot be assessed. Numerical results for daily use time are also not reported in the information, although the study summary mentions daily use as an aim.

The design is listed as non-randomized and single-group, so the record does not describe a randomized control comparison. This limits causal interpretation of any observed change over time. The registry’s warning that the arms are not a like-for-like control comparison further cautions against treating the “Amptify First” and “Amptify Second” labels as control and intervention groups.

The record uses clEAR and Amptify DTx in different descriptions, without explaining the relationship between those names. It also does not explain how the two adverse-event labels relate to the single-group design. These reporting ambiguities make it harder to connect the intervention description, outcome assessment, and safety entries.

Eligibility criteria, participant characteristics, recruitment details, the exact masking procedure, and the precise assessment schedule are not reported in the registry record information. The primary timeframe wording combines “Three weeks after hearing aid fitting” with completion of the four week training protocol, but does not clarify the full sequence of assessments.

The analysis plan, analysis population, missing-data amounts and methods, multiplicity handling, and reasons for missing observations are also not reported in the registry record. These omissions constrain evaluation of reproducibility, precision, and the population represented by any estimate.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Auditory Training and Hearing Aid Satisfaction — NCT04230876.
• Registry record last updated 2022-09-19; status last verified 2022-08.
• Results first posted 2022-09-19.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry identifies NCT04230876 as a completed Phase 1, non-randomized, single-group study sponsored by Washington University School of Medicine. The listed enrollment is 30, and the listed condition is sensorineural hearing impairment. The record gives a start date of 2020-09-01 and a primary completion date of 2021-02-28.

The intervention is auditory brain training games and activities. The primary outcome is change in hearing-aid satisfaction measured with COSI, described as a participant-defined improvement scale. A secondary outcome listed is change in percent words correct on speech-perception measures.

The numerical primary-outcome results and key analysis details are not reported in the registry record information. The design is not a randomized control comparison, and the registry cautions that the listed arms are not like-for-like controls. Serious-adverse-event entries report 0 events and 0 deaths for each of the two listed labels, whose relationship to the single-group design is not explained.