This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Speech Locator In-car Performance Evaluation (NCT05054816), a na na study. The primary outcome is Speech Clarity.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05054816 |
| Phase | NA |
| Condition | Hearing Loss |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Sonova AG |
| Results posted | Yes |
2. Clinical Question
Population
Participants with hearing loss. The registry record lists an enrollment of 20; it also states that two participants’ data were omitted because their results suggested they did not understand the task.
Intervention
An investigational adaptive directional microphone strategy applied to recordings of talkers in a moving car.
Comparator
An omnidirectional microphone strategy and a fixed directional microphone strategy. Participants rated recordings processed with the different strategies while listening through commercially available and individually prescribed hearing aids.
Primary question
How do participants rate the speech clarity of recordings processed using the investigational strategy and the two comparator strategies?
The central outcome is a listener rating, not an objective measure of speech recognition. Participants were asked to rate clarity using a continuous slider, with ratings intended to reflect how intelligible the speech sounded. Each participant experienced a within-subject repeated-measures procedure, so the intended comparison involved ratings across strategies from the same listeners rather than independent groups of listeners assigned to separate strategies.
The registry record describes the study as single-group and lists allocation as not applicable. It does not describe a randomized allocation of participants to strategies. Stimuli were randomized, according to the study summary, but randomizing the order of listening materials is distinct from randomly assigning participants or treatments. The available record does not report numerical strategy-specific ratings or a numerical estimate of the differences between strategies. As a result, the clinical question can be described, but the magnitude and precision of any observed comparison cannot be assessed from the reported information.
3. Trial Design
Speech Locator In-car Performance Evaluation is registered as a completed, single-group study. It lists an enrollment of 20 and participants with hearing loss. The record gives a start date of 2022-02-11 and a primary completion date of 2022-03-11. The phase is listed as not applicable. Sonova AG is named as the sponsor.
The study evaluates three microphone processing strategies: an investigational adaptive directional microphone, an omnidirectional microphone comparator, and a fixed directional microphone comparator. Participants listened to recordings of talkers in a moving car. The recordings were streamed through commercially available and individually prescribed hearing aids, and ratings were completed onsite in the lab. The summary describes a training session and a within-subject repeated-measures procedure, with stimuli randomized.
A within-subject design means that the same participants contribute ratings under the different listening conditions. This can support comparisons that account for stable differences between listeners, because each person serves as their own reference across conditions. It does not, by itself, establish that the order of strategies was randomized or that all other features of listening were held constant. The registry record says the stimuli were randomized but does not report further details about order, counterbalancing, or the implementation of the repeated-measures procedure.
The primary outcome is speech clarity, rated using a continuous scale from 0 (worst) to 100 (best). The stated timeframe is up to 6 hours over 3 2-hour sessions. The record says two participants’ data were omitted because their results suggested that they did not understand the task. It does not report the number of participants contributing to each specific analysis, the analysis population definition, or how incomplete ratings were handled.
The record does not report a randomized participant allocation, a separate parallel control group, or a blinded assessment. Masking is listed as none. These features matter when interpreting comparisons: the design is a structured listening evaluation among participants exposed to multiple strategies, not a randomized, masked, between-group trial. Numerical outcome results and comparative estimates are 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
| Stage | Participants With Hearing Loss |
|---|---|
| STARTED | 20 |
| COMPLETED | 20 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Two participants' data were omitted due to their results suggesting that they did not understand the task.
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.
| Characteristic | Unit | Participants With Hearing Loss. |
|---|---|---|
| Participants analysed | 20 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 9 |
| Age, Categorical: >=65 years | Participants | 11 |
| Age, Continuous | years | 68 (SD 8.2) |
| Sex: Female, Male: Female | Participants | 8 |
| Sex: Female, Male: Male | Participants | 12 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 20 |
| Region of Enrollment: Canada | Participants | 20 |
| Hearing loss severity: Mild | Participants | 15 |
| Hearing loss severity: Moderate | Participants | 3 |
| Hearing loss severity: Moderate-Severe | Participants | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Speech Clarity, measured over Up to 6 hours over 3 2-hour sessions.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Error |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is speech clarity, measured as a participant rating on a continuous slider from 0 (Very unclear) to 100 (Very clear). The scale description includes descriptors at 0, 25, 50, 75, and 100, ranging from very unclear to very clear. Participants were instructed to rate the clarity of speech after listening to sound samples. The registry describes the endpoint as a mean, with standard error as the dispersion measure, and gives a timeframe of up to 6 hours over 3 2-hour sessions.
A clarity rating captures the listener’s overall judgment of how clear speech sounds in a particular listening condition. The registry states that clarity ratings are expected to be impacted by speech intelligibility and that participants would rate and compare clarity across the investigational and comparator features. This is a subjective perceptual outcome: it reflects the participants’ ratings, rather than a direct count of correctly recognized words or an objective acoustic measurement.
General statistical context: a mean can summarize ratings across observations, while a standard error describes the precision of an estimated mean. The standard error is not the spread of individual ratings; it concerns uncertainty in the estimated average. Because the same listeners rated multiple strategies, the interpretation of a mean comparison depends on the repeated-measures structure and on how participant-level ratings were analyzed.
The registry record identifies the endpoint and its scale but does not report the observed mean ratings, standard errors, or numerical contrasts between strategies. The extent to which ratings differed, and the precision of any difference, therefore cannot be determined from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies speech clarity as the primary outcome and describes a study in which participants rated recordings processed using an investigational adaptive directional microphone strategy and two comparator strategies. However, it does not report numerical results for the primary endpoint. No strategy-specific means, standard errors, comparative estimates, confidence intervals, or p-values are reported in the registry record. The direction, size, and precision of any observed difference therefore cannot be interpreted from the information available in the record.
The record lists five outcome measures and five analyses, but these counts do not provide the numerical findings or explain the analysis procedures. They also do not show which analyses correspond to particular reported estimates. The primary outcome is identified by title and measurement description, yet the registry record does not include the underlying rating summaries or a numerical comparison of the strategies.
General statistical context: a mean difference would describe the average contrast between listening conditions, while a confidence interval would indicate a range of values compatible with the data and analysis assumptions. A p-value, if reported, would quantify how unusual the data would be under a specified null model; it would not measure the size or practical importance of a difference. None of those numerical results is reported in the registry record, so no conclusion about statistical evidence or precision can be drawn.
The repeated-measures design is relevant to how comparisons should be interpreted. Because participants rated multiple conditions, analyses would ordinarily need to account for the fact that ratings from the same person are related. Treating all ratings as independent could misstate uncertainty. The registry record does not report the model or calculation used for the five analyses, so it is not possible to determine how within-participant dependence was handled.
The study summary states that stimuli were randomized. This may help address order-related influences on listening materials, but it does not establish random assignment of participants to strategies; allocation is listed as not applicable, and the study is described as single-group. The record also lists masking as none. Consequently, the design description should not be read as a randomized, masked comparison between separate groups.
The registry reports that two participants’ data were omitted because their results suggested that they did not understand the task. That information is relevant to the analysis population and to the possible influence of exclusions, but the record does not report the criteria used to judge task understanding, the rating data excluded, or sensitivity analyses. The enrollment figure alone cannot establish how many observations contributed to each endpoint analysis.
Overall, the record supports a description of the research question, scale, listening procedure, and design, but not a quantitative account of the primary outcome. The absence of numerical results in the registry record is not evidence that strategies produced identical ratings, nor does it show that one strategy produced higher ratings. It means that the observed differences and their uncertainty are not reported there.
9. Statistical Methods Explained
General statistical context: the primary outcome is a continuous rating, and the registry describes it using a mean and standard error. A mean represents the average of the included ratings under the analysis definition. A standard error describes the uncertainty in an estimated mean; it is different from a standard deviation, which describes variability among individual observations. A narrow standard error would indicate a more precise estimated mean than a wide one, but the registry record does not report the endpoint’s numerical mean or standard error.
What does a repeated-measures design imply?
In a repeated-measures design, participants contribute ratings under more than one condition. Ratings from the same participant are often related because each participant has their own response tendencies. A suitable comparison accounts for this dependence. General approaches can include analyzing within-participant contrasts or using a model that represents participant-level variation. These are general examples, not claims about the method used in this study: the registry record does not report the statistical model or the details of the analysis.
Accounting for within-participant dependence matters for uncertainty. If related ratings are treated as though they came from unrelated people, the estimated uncertainty may not reflect the study structure. The direction and magnitude of any effect of such a choice depend on the data and analysis. Since the registry record does not give the numerical results or analysis specification, the reader cannot evaluate whether the reported uncertainty, if any, reflects the repeated-measures design.
How should the rating scale be understood?
The scale runs from 0 (worst) to 100 (best), with verbal descriptors at 0, 25, 50, 75, and 100. Participants used a continuous slider, so the rating was not restricted to those descriptor values. Treating a rating as continuous is a modeling choice that allows summaries such as means, but the resulting average should still be understood as a summary of subjective judgments on the stated scale. It is not a direct measure of the proportion of words understood.
General statistical context: a confidence interval can express uncertainty around an estimated mean or contrast, under the assumptions of the analysis. The interval’s width reflects both the amount and variability of information and the analysis method. Its interpretation depends on the study design and model. No confidence interval is reported in the registry record for this endpoint, so its precision cannot be assessed numerically.
What role does randomization play?
The study summary says that stimuli were randomized. Randomizing stimuli can concern the order in which listening materials are presented; it is not the same as randomizing participants to separate treatment groups. The record labels the study as single-group and allocation as not applicable. It does not report whether strategy order was randomized or counterbalanced, or how order effects were handled in the analysis. The record also lists masking as none.
General statistical context: randomization can reduce systematic differences between assigned groups, while masking can limit some influences on measurement and assessment. Those concepts should not be attributed to this study beyond what its record states. The available design description supports a within-subject listening evaluation, but not a claim of randomized allocation to three independent groups.
What can be said about planning calculations?
The registry record includes assumptions for a planning illustration based on an observed effect: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect stated as a fraction of the observed effect. The record specifies that the illustration is not the trial’s own design. It is a planning exercise, not an observed trial result and not observed power. No numerical planning results are reported in the registry record, so no participant requirement can be stated from the information available.
General statistical context: sample-size illustrations depend on assumptions about the effect to be detected, variability, allocation, and the chosen error rate. Changing those assumptions changes the planning result. Such an illustration does not establish the actual design rationale or guarantee that a study will produce a precise estimate. The registry record does not report the study’s own sample-size justification, and the planning assumptions should not be mistaken for a protocol description.
What can be inferred from a significance test?
General statistical context: a significance test compares the observed data with a null model specified by the analysis. A p-value does not state the probability that the null hypothesis is true, and it does not measure the practical size of a difference. Interpretation is stronger when a numerical effect estimate and an interval describing uncertainty are reported alongside any test. The registry record reports no numerical p-values, intervals, or comparative estimates for the primary outcome.
Over-dispersion is a general concern when observed variation is greater than an analysis model allows. If present and unaccounted for, the model may understate uncertainty. Whether over-dispersion is relevant depends on the outcome and model. The registry record does not report a model diagnostic or an over-dispersion assessment; there is no basis to say whether it occurred in this study.
Finally, the registry lists five analyses but does not describe their statistical specifications. It does not report adjustments for multiple comparisons, treatment of missing ratings, covariate adjustment, or analysis-population definitions. Those omissions limit the ability to reproduce or fully evaluate the inferential procedure. The design and endpoint can be described, but the numerical evidence and the methods needed to interpret that evidence are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists five outcome measures and five analyses. Speech clarity is identified as the primary outcome, but the record does not report how the other outcomes relate to the primary question, whether all analyses were planned, or whether any adjustment for multiple comparisons was used. General statistical context: when several outcomes or contrasts are tested, the chance of finding at least one apparently notable result can increase if each is interpreted without regard to the others. Methods for addressing multiplicity depend on the analysis plan and the goals of the study. No such method is reported in the registry record.
The record states that two participants’ data were omitted because their results suggested that they did not understand the task. It does not report how task understanding was assessed, whether the exclusion rule was defined in advance, how many ratings were omitted, or whether analyses were conducted with and without those participants. The record also does not describe the handling of any other missing or incomplete ratings.
The enrollment is listed as 20, but the registry record does not define the analysis population for each outcome or report the number of observations included in each analysis. The two omitted participants’ data should not be treated as proof that all remaining participants contributed complete data. The number of participants analyzed cannot be established from the enrollment figure and exclusion statement alone.
General statistical context: excluding observations can affect both the estimate and its uncertainty, especially if the reasons for exclusion are related to the ratings. A sensitivity analysis can examine whether conclusions change under alternative reasonable analysis choices. The registry record does not report such analyses. It also does not report an interim-analysis plan or a detailed statistical analysis plan.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Participants With Hearing Loss. | 0 | 20 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Participants With Hearing Loss. | 0 of 20 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Participants With Hearing Loss. | 0 of 20 |
The registry lists a group of participants with hearing loss, with 20 at risk for serious adverse events and 0 serious adverse events recorded. It also lists 20 at risk for other adverse events and 0 other adverse events recorded, with 0 deaths. No serious adverse event terms are listed.
These figures describe what is recorded for the study group; they do not establish that no adverse events could occur or that every possible event was captured. The registry record does not report the adverse-event observation period, event definitions, collection procedures, or further detail about how events were assessed. It also does not provide event-level descriptions because no serious-event terms are listed.
General statistical context: a zero count is an observed count, not proof that the underlying risk is zero. The interpretation of an adverse-event count depends on the number of people observed, duration and completeness of follow-up, and event ascertainment. The registry reports the at-risk counts, but the information available does not permit a fuller assessment of surveillance or exposure time. These safety figures should be read as registry-reported counts, not as a general guarantee about safety.
12. What the Result Does, and Does Not, Mean
The registry record describes a listening study in which participants with hearing loss rated speech clarity for recordings processed with an investigational adaptive directional microphone strategy and two comparator strategies. It specifies the rating scale, the listening context, and a repeated-measures approach. It also reports that two participants’ data were omitted because their results suggested that they did not understand the task.
Those details explain what the study set out to measure, but they do not reveal the observed primary outcome. Numerical means, standard errors, strategy comparisons, confidence intervals, and p-values are not reported in the registry record. It is therefore not possible to say how participants rated the strategies on average, whether ratings differed, or how precise any comparison was.
General statistical context: a result can be described in terms of both its estimated size and uncertainty. A small estimated difference with a narrow interval conveys different information from the same estimate with a wide interval. A statistical test alone would not describe the practical size of a difference. Here, the registry record does not report the estimates or uncertainty needed for either interpretation.
The study’s structure also limits what its design description can establish. It is listed as single-group, with allocation not applicable and masking none. Participants experienced multiple strategies, and stimuli were randomized, but the record does not report random assignment of participants to separate groups. The record does not report how the repeated ratings were modeled or how potential order effects were addressed.
The recorded adverse-event counts are 0 serious events, 0 other events, and 0 deaths among the listed group. These are registry counts, not proof that risk is absent. In addition, the registry does not report an observation period or collection details for these outcomes.
In short, the record supports a description of the study question and procedures, but not a conclusion about the comparative speech-clarity results. It does not establish that the strategies produced the same ratings or different ratings. Those interpretations require numerical outcome estimates and their uncertainty, which are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically interesting because its central measure is a listener rating collected across multiple conditions from the same participants. That structure raises practical questions about how subjective ratings should be summarized, how within-person dependence should be represented, and how to communicate uncertainty. The registry record identifies a continuous scale and a repeated-measures procedure, making those issues relevant even though it does not report the model or numerical results.
The endpoint also highlights the distinction between a perceptual measure and a direct performance measure. Participants rated how clear speech sounded; the record says these ratings were expected to be impacted by intelligibility. A clarity rating can capture an aspect of listening experience, but it is not equivalent to a count of correctly understood speech. Interpretation should remain tied to the outcome actually measured.
The design description offers a useful example of why different kinds of randomization should not be conflated. Stimuli were randomized, while participant allocation is listed as not applicable and the study is described as single-group. Randomizing presentation materials does not, by itself, create randomized comparison groups. Clear description of the randomization unit is important when readers evaluate design strengths and limitations.
The record also illustrates why exclusions and analysis populations need explicit reporting. Two participants’ data were omitted because their results suggested they did not understand the task, but the record does not explain how that judgment was made or what analyses were performed with respect to the omitted data. Such information helps readers understand who contributed to the estimates and whether the conclusions could depend on analysis choices.
Finally, the registry’s endpoint description is not a substitute for results. Without numerical estimates and uncertainty, readers cannot assess the magnitude or precision of the comparisons. This distinction is central to statistical literacy: a clearly stated question and method do not themselves reveal what the observed data showed.
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 registry record leaves important details unavailable for interpreting the comparison. It describes a single-group, repeated-measures evaluation, but does not report the statistical model, the unit of analysis, or how ratings from the same participant were handled. The record says stimuli were randomized, but does not report strategy order, counterbalancing, or the approach to potential order effects. Masking is listed as none.
The record does not report numerical primary-outcome results. Without the means, standard errors, contrasts, or other estimates, the direction, size, and precision of the speech-clarity comparisons cannot be assessed. It also does not report confidence intervals or p-values. Although five outcome measures and five analyses are listed, their specifications and any multiplicity approach are not reported.
Two participants’ data were omitted because their results suggested that they did not understand the task. The registry record does not explain the task-understanding assessment, say whether the criterion was prespecified, report how many ratings were excluded, or describe sensitivity analyses. It also does not report the analysis population or how any other missing ratings were handled.
The endpoint is a subjective rating on a continuous scale. Such ratings summarize participants’ perceptions, not an objective count of speech items understood. The study used recordings of talkers in a moving car and listening through commercially available and individually prescribed hearing aids, but the registry record does not report enough procedural detail to assess how broadly the results might apply beyond this evaluation.
The design and reporting limitations are distinct: a single-group repeated-measures design can generate within-participant comparisons, but a reader still needs the analysis method and outcome estimates to judge those comparisons. Neither the study’s own sample-size justification nor a detailed statistical analysis plan is reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Speech Locator In-car Performance Evaluation — NCT05054816.
- Registry record last updated 2025-08-17; status last verified 2021-09.
- Results first posted 2025-08-17.
- 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.
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18. Record Summary
Speech Locator In-car Performance Evaluation is a completed, single-group study sponsored by Sonova AG. The registry lists an enrollment of 20 participants with hearing loss. The study evaluated an investigational adaptive directional microphone strategy against omnidirectional and fixed directional microphone strategies using ratings of recordings of talkers in a moving car.
The primary outcome was speech clarity, rated on a continuous scale from 0 (worst) to 100 (best), with a stated timeframe of up to 6 hours over 3 2-hour sessions. Participants listened through commercially available and individually prescribed hearing aids and completed ratings onsite. Stimuli were randomized, and the procedure was described as within-subject repeated measures. Masking was listed as none, and allocation as not applicable.
The registry reports that two participants’ data were omitted because their results suggested that they did not understand the task. It records 0 serious adverse events, 0 other adverse events, and 0 deaths among the listed group. Numerical primary-outcome results, comparative estimates, and analysis details are not reported in the registry record.