Audiobooks for Hearing Loss App as Auditory Training: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Audiobooks for Hearing Loss App as Auditory Training (NCT04231396), a na na study. The primary outcome is Audiobooks Efficacy: Change in Slope of Curve for SNR Loss Scores on a Scale/Week for Partial BKB-SIN Hearing Test.

2. Clinical Question

This question concerns change over time within the participating group, rather than a contrast between people assigned to the app and people assigned to another intervention or control. The registry describes the app as having user-selectable features intended to provide auditory training, and describes measurement of listener abilities and adherence. However, the numerical primary outcome result and the results for the listed secondary outcomes are not reported in the registry record. The record therefore does not establish the size or precision of any observed change, or whether the change was associated with app use.

3. Trial Design

The study is registered as a completed, single-group trial with an enrollment of 27. Its listed allocation is NA, and masking is listed as none. The registry does not describe a randomized assignment or a separate control arm. The intervention is the Audiobooks for Hearing Loss App, classified as other.

The brief study description characterizes the app-use period as a six-week trial. The arm description gives a broader schedule: participants would be seen weekly for 12 weeks and use the app during the final six weeks, on their own for at least two hours per week. It also describes 12 weekly in-home visits. The registry record does not fully report the procedures for those visits; the available arm description begins to mention partial BKB-SIN testing during the first six weeks but is incomplete.

The primary outcome timeframe is six weeks. Its description places the slope measurement in the auditory-training portion, identified as weeks 7–12. The study dates are listed as starting 2021-02-25 and reaching primary completion on 2021-09-14. The status is completed. These design details describe the registered plan and schedule; they do not provide numerical outcome findings.

Because this is a single-group study without a separate comparator, changes across time can be described for the participants, but the design does not directly estimate a difference between the app and a control condition. Further information about eligibility criteria, participant characteristics, the detailed visit schedule, and the statistical analysis plan is not reported in the registry record.

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

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 Audiobooks Efficacy: Change in Slope of Curve for SNR Loss Scores on a Scale/Week for Partial BKB-SIN Hearing Test, measured over 6 weeks.

The primary endpoint is described as the change in slope of scores on the partial BKB-SIN hearing test, expressed in units on a scale per week. BKB-SIN is described as a speech-in-noise test, with scores based on normative sample data and decibel measures. The stated range starts at 0 dB and extends to 15+ dB. The record gives interpretive bands of 0–3 dB for hearing normal, 3–7 dB for mild SNR loss, 7–15 dB for moderate SNR loss, and >15 dB for severe SNR loss. Lower scores mean a better outcome.

A slope describes how a measure changes over time. In this study, the endpoint focuses on the direction and rate of change in partial BKB-SIN scores during the six-week auditory-training period, rather than only on a single score at one visit. The registry describes estimating slopes for weeks 7–12 and using isotonic regression with the assumption that scores would be non-increasing over those weeks.

Speech-in-noise performance is relevant to the stated study aim of measuring listener abilities during auditory training. The registry defines the primary measure as a mean and identifies standard deviation as its dispersion measure. However, the estimated mean change, standard deviation, and other numerical results for this endpoint are not reported in the registry record. Its magnitude and precision therefore cannot be assessed from the registered results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure: change in the slope of partial BKB-SIN scores, reported in units on a scale per week. The registry identifies the summary parameter as a mean and standard deviation as the measure of dispersion. A mean describes the average value in a group. A standard deviation describes how spread out individual values are around that mean. Neither numerical summary is reported for the primary result, so the record does not reveal the observed average change or the variability among participants.

What does a slope represent?

In general, a slope describes the rate and direction of change in a measurement over time. A slope for repeated hearing-test scores can summarize whether scores tend to rise, fall, or remain similar across the measurement period. Here, the endpoint description specifies a change in slope, and the timeframe is six weeks. The record identifies weeks 7–12 as the auditory-training period for measuring BKB-SIN slopes. It does not provide a numerical slope estimate or a detailed formula explaining how the change in slope was calculated.

Why use isotonic regression?

The registry says a smoothing method, isotonic regression, was used through isoreg() in R. In general, isotonic regression fits values subject to a monotonicity constraint: fitted values must move in one direction or remain level as the ordered observations progress. The stated constraint in this study is non-increasing BKB-SIN scores over the six weeks. Since lower scores are described as better, this constraint encodes a pattern in which scores do not increase across the period. The method can smooth noisy repeated measurements while respecting that constraint.

That constraint should be kept distinct from the empirical result. It expresses an assumption used in the statistical method; it does not establish that every participant improved, or that the unprocessed observations followed a steadily improving pattern. The registry does not report the fitted values, the underlying participant-level observations, or a numerical estimate of the primary endpoint. It also does not report an alternative analysis without the monotonicity constraint, so the impact of that modeling choice cannot be assessed.

How should uncertainty be assessed?

In general, an estimate describes the observed pattern, while an uncertainty measure describes how much statistical imprecision surrounds it. A confidence interval is one common way to express uncertainty around an estimate; a p-value addresses compatibility with a specified null hypothesis under an analysis model. Neither is a substitute for the effect estimate itself. The registry record does not report a confidence interval or p-value for the primary outcome, and it does not provide the numerical estimate needed to describe the result’s magnitude.

The registry identifies a mean and standard deviation as the primary outcome’s summary format, but the numerical values are absent. The record lists one analysis, without a detailed account of the model, the exact test, or the uncertainty procedure. Consequently, it is not possible to evaluate the analysis’s precision or reproduce the reported result from the registry record.

What does the single-group design allow?

In general, repeated measurements in one group can describe how a measure changes over time among those participants. A separate comparison group can help distinguish changes associated with an intervention from changes that might also occur without it. This registry describes a single group and no comparator, so it does not provide a between-group treatment contrast. Masking is listed as none. These features limit how strongly an observed time trend could be attributed to the app, even if the numerical trend were reported.

The record also lists two secondary measures: positive responses to a final question asking whether participants would buy or recommend the app, and the overall mean score of weekly goals met. These measure usability responses and adherence, respectively, rather than the primary speech-in-noise outcome. Their results are not reported in the registry record. The statistical methods used for those measures, including how missing survey responses or weekly goal data were handled, are also not reported in the registry record.

Planning illustrations based on an observed effect are not observed power and are not evidence about the result. Any such illustration is distinct from the study’s actual design and does not replace a reported estimate with its uncertainty. The registry record does not report a sample-size justification for this trial.

10. Multiplicity, Missing Data and Analysis Populations

The record identifies one primary outcome and two secondary outcomes, for three outcome measures in total. It lists one analysis, but does not describe a plan for handling multiple outcomes or multiple statistical tests. Whether any multiplicity adjustment was used is not reported in the registry record. Without that information and without numerical results, the risk of interpreting chance findings across several outcomes cannot be assessed.

Missing-data procedures are not reported in the registry record. The record does not state how incomplete BKB-SIN measurements, missed visits, or missing usability-survey or adherence information were handled. It also does not report whether all enrolled participants contributed data to each outcome, or how many had usable measurements for the primary analysis. Enrollment is 27, but that does not establish the analysis population or the number of observations included in an outcome estimate.

The analysis populations are not reported in the registry record. In particular, the record does not specify whether the primary analysis included all enrolled participants, only participants with measurements across the relevant weeks, or another defined group. The detailed statistical analysis plan, including any prespecified handling of outliers or deviations from the weekly schedule, is also not reported. These omissions limit assessment of how the analysis may have been affected by incomplete data or participant exclusions.

11. 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 adverse-event record lists 27 participants at risk for serious adverse events and zero serious adverse events. It also lists 27 participants at risk for other adverse events and zero other adverse events. Deaths are recorded as zero, and no serious adverse-event terms are listed.

These figures describe the events recorded for this study group. They do not establish that an event could not occur, and they do not quantify risk beyond the observed participants and the reporting period. The adverse-event timeframe, collection procedures, and criteria used to classify events are not reported in the registry record. The record also does not provide further information about completeness of event monitoring.

Because the study is single-group and includes 27 participants, these counts should be read as descriptive safety reporting, not as a comparison between the app and another condition. The zero counts do not provide a comparative estimate of safety, and they do not address the primary speech-in-noise outcome. No conclusion about safety relative to another intervention can be drawn from these figures.

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

The record establishes that a completed, single-group study evaluated an audiobook app used for auditory training by hearing-aid and cochlear-implant users. It specifies a primary outcome based on change in the slope of partial BKB-SIN scores over a six-week training period. It also lists usability and adherence outcomes. The numerical results for these outcomes are not reported in the registry record.

As a result, the record does not show how much the primary score changed, whether the observed pattern was precise, or whether any change was statistically distinguishable from no change. It does not show the proportion of positive responses to the usability question or the mean score for weekly goals met. The method’s non-increasing-score assumption describes how the primary measure was smoothed, not what the numerical result was.

The study design also matters for interpretation. With one group and no separate comparator, a measured change over time would not on its own establish that app use caused the change. The lack of masking is another feature of the design. These are limits on what the design can establish, not claims about whether the app did or did not have an effect.

The posted record therefore supports an account of the intended intervention, schedule, and statistical approach, along with the adverse-event counts. It does not support a quantitative conclusion about efficacy, a comparative treatment effect, or the precision of any primary or secondary outcome. Those conclusions would require reported outcome estimates and enough analysis detail to interpret them.

13. Why This Trial Matters Statistically

This trial is statistically notable because it frames auditory-training assessment as change in a repeated speech-in-noise measure, rather than a single endpoint score. A slope can describe how scores evolve during the training period. The record also makes explicit that isotonic regression was used with a non-increasing constraint, illustrating how a modeling choice can reflect an expected direction of change.

That choice also highlights why methods and results must be read together. A monotonicity constraint can shape fitted values, but it is not a result in itself. Without the underlying numerical estimate, variability, and uncertainty, readers cannot assess how large the change was or how dependent the analysis was on its constraint. The registry record does not report those numerical details.

The single-group design is another important statistical feature. It can describe outcomes over time for participants in the study, but it does not provide a direct comparison with a group not using the app. This distinction matters when interpreting time trends: a within-group change and a comparative treatment effect answer different questions.

Finally, the record lists a primary outcome alongside usability and adherence measures, but does not report their numerical findings or a multiplicity strategy. This makes it difficult to understand the full pattern of outcomes or assess how uncertainty across multiple measures was handled. The registration is useful for identifying the intended endpoint and analysis approach, while the missing outcome estimates limit statistical interpretation.

14. 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 main limitation for interpreting this trial is that numerical primary and secondary outcome results are not reported in the registry record. Without effect estimates and measures of uncertainty, the magnitude, direction, and precision of changes cannot be assessed. The record also does not report a confidence interval, p-value, or detailed analysis output.

The design is single-group, with no separate comparator and no masking. Therefore, the registered design does not provide a direct between-group comparison, and a change over time would not by itself identify an effect attributable to the app. The enrollment is 27; the record does not report a sample-size justification or the number of participants contributing data to each analysis.

The schedule is described in more than one way. The brief description calls the app-use study a six-week trial, while the arm description gives weekly visits over 12 weeks with app use during the final six weeks. The primary endpoint description identifies weeks 7–12 as the auditory-training period. These descriptions indicate a broader visit schedule than the app-use period, but the full visit procedures are not reported in the registry record.

The primary analysis uses isotonic regression and assumes non-increasing scores over the measurement period. The registry record does not report results from an alternative method or provide enough detail to assess the sensitivity of the findings to that constraint. Participant ages, missing-data handling, analysis populations, multiplicity procedures, and detailed statistical-plan information are also not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Audiobooks for Hearing Loss App as Auditory Training — NCT04231396.
• Registry record last updated 2022-01-14; status last verified 2022-01.
• Results first posted 2022-01-14.
• 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.

18. Record Summary

The registry record describes a completed, single-group study of the Audiobooks for Hearing Loss App as auditory training for hearing-aid and cochlear-implant users. Enrollment is 27; allocation is listed as NA and masking as none. Weekly in-home visits are described over 12 weeks, with app use during the final six weeks for at least two hours per week on participants’ own time.

The primary outcome is change in slope of partial BKB-SIN scores during weeks 7–12. The analysis description specifies isotonic regression with non-increasing scores as an assumption. Two secondary outcomes concern positive responses to a usability question and weekly goals met. Numerical results for the primary and secondary outcomes are not reported in the registry record. The adverse-event record lists zero serious adverse events, zero other adverse events, and zero deaths among 27 participants at risk.