Direct-to-Consumer Hearing Aids and Listening Effort: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Direct-to-Consumer Hearing Aids and Listening Effort (NCT05855005), a na na study. The primary outcome is Diapix Conversation Task: Average Time Per Correctly Identified Difference.

2. Clinical Question

The registry describes a conversation between a participant and a communication partner. They discuss pictures with slight differences and try to find all the differences through discussion. The primary outcome is the average time per correctly identified difference. A shorter time is described as indicating improved efficiency on this task.

The central statistical question is whether task performance differs between the conditions with and without hearing aids. Because the design is single-group, the comparison is not between independently assigned treatment and control groups. The registry does not report the order of the two task conditions, whether order was randomized, or how the within-participant comparison was analyzed. Those details are not reported in the registry record.

Listening effort is part of the study’s stated motivation, but the primary outcome is time per correct difference rather than a direct measure of effort. Pupillometry and a Recall Repeat Task are listed as secondary outcomes. Their results and their relation to the primary task are not reported in the registry record.

3. Trial Design

The registry identifies this as a completed, single-group device study of direct-to-consumer hearing aids. The listed enrollment is 30. The allocation field is NA, and masking is listed as NONE. The record gives no randomized parallel-group control condition; instead, the primary task is described as occurring both with and without hearing aids after fitting.

The study is sponsored by Northwestern University. The recorded start date is 2022-10-25, and the primary completion date is 2023-12-01. The phase is listed as NA. These registration details describe the study framework and timeline, but do not explain the rationale for the enrollment target or the statistical design choices.

The task is described as taking place at the first study visit, typically 2 hours after hearing aid fitting. A participant and communication partner discuss pictures with slight differences, attempting to identify them through conversation. The primary measure is average time per correctly identified difference. The registry also lists pupillometry and a Recall Repeat Task as secondary outcomes.

The design description leaves important operational details unresolved. The record does not report how participants were recruited, the eligibility criteria beyond the listed hearing-loss conditions, whether a participant’s communication partner was the same across conditions, or how task order and practice effects were handled. It also does not describe the fitting protocol beyond the summary’s statement that devices were programmed to individual hearing losses. These details are not reported in the registry record.

Although the study status is COMPLETED, no primary outcome analysis is listed. The record gives 2 outcome measures and 0 analyses. Consequently, the registered design can be described, but the effectiveness or magnitude of any observed change cannot be evaluated from the posted results. Completion status alone does not establish that outcomes were analyzed or that a particular result was found.

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 Diapix Conversation Task: Average Time Per Correctly Identified Difference, measured over Task is completed at first study visit (typically 2 hours) after hearing aid fitting, with and without hearing aids..

The primary endpoint is the average time per correctly identified difference in the Diapix Conversation Task, measured in minutes. The task asks a participant and communication partner to discuss pictures containing slight differences and identify those differences through conversation. The measure focuses on how long the pair takes for each correctly identified difference, rather than simply counting correct responses.

Time is used as an indicator of conversation efficiency in this task. The registry states that a decrease in time indicates improved task efficiency. This interpretation is specific to the task: it describes speed in identifying picture differences through discussion, not every aspect of communication or listening effort in everyday settings.

The registry describes the task as completed with and without hearing aids at the first study visit, typically 2 hours after fitting. It does not report whether the conditions were administered in a fixed or randomized order, how an incomplete task would be handled, or whether the average was calculated across all correctly identified differences or under another rule. Those procedures are not reported in the registry record.

The endpoint is a continuous measure. A mean can communicate the average task time, while a standard deviation can describe how much individual observations vary around that average. Neither a mean nor a standard deviation for the primary endpoint is reported in the registry record. There is therefore no posted estimate of the size or direction of the observed difference between the hearing-aid conditions.

Because the endpoint is task time, it should not be treated as a direct measure of listening effort. The study’s stated objective concerns listening effort and effective communication, and pupillometry and a Recall Repeat Task are listed as secondary outcomes. Their measurement details and results are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary measure is continuous: it records time per correctly identified difference in minutes. The registered summary parameter is the mean, with standard deviation as the dispersion measure. The mean describes a central average, while the standard deviation describes variation in observations around that average. These are descriptive quantities; they do not by themselves show whether a difference between conditions is compatible with chance or how precisely it is estimated.

What would a condition comparison estimate?

Because the same single-group study describes task performance with and without hearing aids, a natural comparison would be the within-participant change in task time. General statistical principle: pairing can be useful because each participant serves as their own reference, reducing the influence of stable between-person differences. The analysis would need to respect that pairing. The registry does not report a model, test, or other method used for this comparison, so the actual analysis approach is not reported in the registry record.

The record’s sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustration is not a description of the registered single-group design: the study is not recorded as a two-arm randomized comparison. The assumptions state that the effect to detect is a stated fraction of the observed effect. No numerical planning result is included in the registry record. Any such planning illustration is not observed power; it is a hypothetical sample-size calculation under its stated assumptions.

Why do uncertainty estimates matter?

A confidence interval is a general way to express uncertainty around an estimated effect. It gives a range of values compatible with the data and statistical model, rather than presenting the point estimate as exact. Its width depends on factors such as the amount of information in the data and variability in the outcome. A confidence interval can help distinguish a relatively precise estimate from one that remains uncertain. The registry does not report a confidence interval for the primary endpoint.

A significance test addresses a different question: how compatible the observed data are with a specified null model. A p-value is not the probability that the null hypothesis is true, nor does it measure the size or importance of an effect. Interpretation should consider the effect estimate and its uncertainty alongside the testing framework. No p-value or test result for the primary outcome is reported in the registry record.

How can variability affect the analysis?

Standard deviation is a familiar measure of spread for continuous outcomes, but it may not fully describe a distribution that is strongly skewed or has influential extreme observations. Task times can, as a general matter, have a long upper tail when some performances take substantially longer than others. That is a methodological possibility, not a finding about this trial. Reviewing the distribution and residual behavior can help assess whether a mean-based analysis and its model assumptions are reasonable. The registry does not report distributional checks or diagnostics.

Over-dispersion is a general concern when the observed variability exceeds what a statistical model assumes. If that happens, model-based standard errors can be too small and confidence intervals too narrow unless the model is adapted. This concept is most directly relevant to models for counts or rates; the primary endpoint is continuous time. The registry does not report an analysis model, so it is not possible to determine whether over-dispersion was assessed or relevant to the reported analysis.

What design details shape the interpretation?

Repeated task conditions can be affected by order and learning. A participant may become more familiar with the task after an earlier attempt, or fatigue may affect later performance. General methods include randomizing or counterbalancing task order and accounting for period or sequence in the analysis when appropriate. The registry does not report task order, randomization of order, or an adjustment for these effects. It is therefore not possible to judge from the record whether order effects were controlled.

The registry’s single-group designation and lack of masking also matter for interpretation. There is no separate randomized control group recorded, and masking is listed as NONE. These features do not invalidate a within-participant task comparison, but they limit what can be separated from the intervention condition and may leave expectations or other time-related influences unaccounted for. Whether such influences occurred is not reported.

The absence of a listed analysis is central. The record gives 0 analyses, so there is no reported estimate, model specification, standard error, confidence interval, or hypothesis test to explain. No recalculation from summary statistics is possible from the registry record, and the sponsor’s own analysis cannot be compared with an independent recalculation. Statistical interpretation must therefore remain at the level of the registered design and endpoint.

10. Multiplicity, Missing Data and Analysis Populations

The record lists the Diapix Conversation Task measure as the primary outcome and lists pupillometry and a Recall Repeat Task as secondary outcomes. It reports 2 outcome measures and 0 analyses. The results and statistical tests for these outcomes are not reported in the registry record.

When a study examines multiple outcomes or performs multiple tests, the chance of at least one apparently unusual result can increase. General approaches to multiplicity include identifying a primary outcome in advance, using a testing hierarchy, or adjusting the interpretation of multiple tests. The registry identifies a primary measure but does not report a multiplicity procedure, a hierarchy among secondary outcomes, or how any multiple comparisons were handled. These details are not reported in the registry record.

Missing-data handling is also not described. The record does not state whether missing task measurements occurred, how incomplete tasks were treated, or whether any imputation or sensitivity analysis was planned or conducted. A complete-case analysis, for example, can be biased if the availability of outcome data is related to performance; that is a general methodological concern, not a claim that it occurred.

Analysis populations are not reported in the registry record. The enrollment entry is 30, but the record does not specify who was included in an outcome analysis, whether all enrolled participants were expected to contribute measurements in both conditions, or how exclusions were handled. No interim analyses or stopping rules are described; these are not reported in the registry record. With no listed analysis, the record does not permit evaluation of these choices or their consequences.

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

The registry record establishes that the study was completed and identifies a primary measure intended to capture conversation-task efficiency. It does not report the numerical outcome data or an analysis. The posted results therefore do not show whether average task time was lower, higher, or similar with hearing aids compared with without hearing aids. They also do not show the uncertainty around a condition difference.

This absence of an estimate is not evidence that the conditions were equivalent, and it is not evidence that the intervention changed performance. Equivalence requires an appropriately designed analysis with a defined margin and adequate precision; such details are not reported in the registry record. Likewise, completion status and enrollment do not establish that the study found a particular result.

The primary measure is task time per correct picture difference. Even a reported change in that measure would apply directly to the described task and its study conditions. It would not automatically establish a change in listening effort, because task efficiency and effort are related but distinct concepts. Nor would task performance alone establish effects on communication in everyday settings. The registry’s secondary outcomes could provide complementary evidence, but their results are not reported.

The record also does not allow a safety conclusion. The adverse-event fields show zero at risk and zero events for the DTC Hearing Aid group. Zero at risk means the entries do not document an observed group from which an absence of events can be inferred.

For readers, the appropriate conclusion is limited: the registry describes a study of DTC hearing aids using a conversation task with and without the devices, but the posted results do not provide the data needed to determine the direction, size, or precision of an effect. Conclusions about listening effort, broader communication, or safety are not supported by the registry record alone.

12. Why This Trial Matters Statistically

This study raises a useful statistical distinction between the question motivating a trial and the outcome used to answer it. The stated aim concerns listening effort and effective communication, while the primary endpoint is time per correctly identified difference in a structured conversation task. A precise endpoint definition helps readers understand exactly what a result would represent—and what it would not represent.

The single-group design also makes the comparison structure important. The registry describes performance with and without hearing aids, but does not record a separate randomized control group. A paired analysis may be suitable for repeated measurements, but its interpretation depends on how the conditions were ordered, how repeated performance was handled, and how missing observations were treated. These choices are not reported in the registry record.

Statistical importance depends on more than whether an effect is declared significant. The size of an estimate and its uncertainty would be needed to judge how compatible the results are with meaningfully different outcomes. Here, the registry contains 0 analyses, so readers cannot assess either magnitude or precision. This is a reminder that a completed trial record without outcome estimates cannot answer the main quantitative question.

The study also illustrates why planning calculations must be distinguished from observed evidence. The stated planning assumptions use an equal allocation between two arms, although the recorded design is single-group. Those planning illustrations are not observed power and do not describe the design as registered. The analysis plan and any sample-size justification are not reported in the registry record.

Finally, statistical interpretation depends on alignment between measurement and claim. Task time can inform task efficiency, but cannot alone establish a broader effect on listening effort or everyday communication. Clear reporting of outcomes, analysis methods, uncertainty, and missing-data handling would be needed to connect the measured task to the study’s broader aims.

13. 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 leaves substantial gaps for interpreting this study’s results. Most importantly, it gives 0 analyses and no primary outcome estimate, standard deviation, confidence interval, or test result. The direction and magnitude of any observed condition difference are therefore not reported in the registry record.

The study is registered as single-group, with allocation listed as NA and masking listed as NONE. The primary task is described with and without hearing aids, but the record does not explain task order or whether order was randomized or counterbalanced. Without those details, potential practice, order, or fatigue effects cannot be assessed. These are possible design considerations, not documented events.

The endpoint description does not explain how incomplete task performance, incorrectly identified differences, or missing measurements were handled. The registry also does not state how the average was calculated beyond describing average time per correctly identified difference. Further details on the analysis population, exclusions, missing-data methods, and statistical model are not reported in the registry record.

The record names pupillometry and a Recall Repeat Task as secondary outcomes but does not provide their results or explain how multiple outcomes were handled statistically. It also does not give further detail about participants, communication partners, hearing-aid fitting procedures, or the study’s sample-size justification. Those items are not reported in the registry record.

Adverse-event entries list zero at risk and zero events, which do not establish that an observed group experienced no events. Together, these limitations mean the record supports a description of the intended task and design, but not an assessment of efficacy, precision, or safety.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: Direct-to-Consumer Hearing Aids and Listening Effort — NCT05855005.
• Registry record last updated 2024-05-29; status last verified 2024-05.
• Results first posted 2024-05-29.
• 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.

17. Record Summary

The registry identifies NCT05855005 as a completed study titled “Direct-to-Consumer Hearing Aids and Listening Effort,” sponsored by Northwestern University. It lists enrollment of 30, a single-group model, allocation NA, and masking NONE. The recorded start date is 2022-10-25, and the primary completion date is 2023-12-01.

The primary outcome is average time per correctly identified difference in the Diapix Conversation Task, measured in minutes. The task is described as taking place with and without hearing aids after fitting. Pupillometry and a Recall Repeat Task are listed as secondary outcomes.

The record reports 2 outcome measures and 0 analyses. No outcome estimates or statistical results are reported in the registry record. The adverse-event fields list zero at risk and zero events, so they do not establish an absence of adverse events.