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 ClearVoice Sound-processing Strategy for AB HiRes 120 Cochlear Implant Users (NCT01066780), a randomized na study. The primary outcome is Speech Perception of Standardized Sentences Presented From Recorded Format in Speech-spectrum Noise.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01066780 |
| Phase | NA |
| Condition | Implant |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 48 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Advanced Bionics |
| Results posted | Yes |
2. Clinical Question
Population
Adults using HiResolution Fidelity 120 cochlear implant sound processing were studied. The registry record lists 48 participants enrolled. The primary-outcome description does not give additional population characteristics, and those are not reported in the registry record.
Intervention
Participants used the ClearVoice sound-processing strategy. The two sequences involved chronic use of ClearVoice MEDIUM and ClearVoice HIGH, each for two weeks, with the order differing between groups.
Comparator
The primary-outcome description compares scores with ClearVoice enabled against scores in quiet at the same follow-up visits. It describes the ClearVoice score minus the quiet score as the difference used for analysis. MEDIUM and HIGH were also used in opposite orders across the two randomized sequences.
Primary question
How did speech perception on standardized AzBio sentences in speech-spectrum noise compare with performance in quiet at the two-week and four-week follow-up visits while participants used ClearVoice MEDIUM or HIGH? The registry record does not report the resulting scores or the estimated differences.
3. Trial Design
This was a randomized, unmasked crossover study of ClearVoice sound processing in adults using HiResolution Fidelity 120 sound processing. The registry lists the study as completed, with 48 participants enrolled. The record gives the study start as 2010-03 and primary completion as 2010-09.
The crossover schedule used two sequences. Group A used ClearVoice MEDIUM chronically for two weeks, followed by ClearVoice HIGH chronically for two weeks. Group B used HIGH first for two weeks, then MEDIUM for two weeks. The primary-outcome description identifies follow-up visits at two weeks and four weeks. Thus, the measurements were taken at successive points while participants used the two ClearVoice settings in different orders.
Randomization describes how participants were assigned to a sequence; it does not mean participants or assessors were masked. The registry lists masking as none. The record does not report sequence-specific enrollment counts, the method used to generate the random allocation, or whether allocation was concealed.
The endpoint description says that two AzBio sentence lists were administered at each follow-up visit with the applicable ClearVoice setting enabled, and that the two scores were averaged. Two sentence lists were also administered in quiet at each visit. The primary analysis was described as using the ClearVoice score minus the quiet score. Further details of the statistical analysis are not reported in the registry record.
The registry lists no statistical analyses. It does not report the number of participants who completed both periods, how period or sequence effects were handled, or whether any participants withdrew. These omissions limit how fully the crossover conduct and analysis can be assessed from 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.
Before assignment: All subjects were fit acutely at the Baseline Visit (Visit 1) with ClearVoice Low and underwent acute speech perception testing. Each subject was then randomized to Group A or Group B.
Overall Study
| Stage | Group A: Received ClearVoice MEDIUM Followed by HIGH | Group B: Received ClearVoice HIGH Followed by MEDIUM |
|---|---|---|
| STARTED | 24 | 24 |
| COMPLETED | 23 | 23 |
| NOT COMPLETED | 1 | 1 |
Reasons for not completing this period:
| Reason | Group A: Received ClearVoice MEDIUM Followed by HIGH | Group B: Received ClearVoice HIGH Followed by MEDIUM |
|---|---|---|
| Withdrawn prior to ClearVoice exposure. | 1 | 1 |
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 | ClearVoice |
|---|---|---|
| Participants analysed | 46 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 29 |
| Age, Categorical: >=65 years | Participants | 17 |
| Age, Continuous | years | 58.5 (SD 16.00) |
| Sex: Female, Male: Female | Participants | 21 |
| Sex: Female, Male: Male | Participants | 25 |
| Region of Enrollment: United States | participants | 46 |
6. Primary Endpoint
The registry lists the primary outcome as Speech Perception of Standardized Sentences Presented From Recorded Format in Speech-spectrum Noise, measured over 4 Weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | percentage of words scored correctly |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is speech perception measured as the percentage of words scored correctly on standardized sentences presented in speech-spectrum noise. The test used the AzBio sentence corpus. According to the registry description, the corpus contains 33 lists of 20 sentences each, with 6 to 10 words per sentence; the lists were equated for intelligibility.
At each two-week and four-week follow-up visit, two lists were administered with ClearVoice MEDIUM or HIGH enabled, and their scores were averaged. Two lists were also administered in quiet at each visit. The endpoint description defines the analysis quantity as the ClearVoice score minus the quiet score. A positive or negative difference would therefore describe the direction of the observed score contrast, but the registry record does not give the numerical differences or their direction.
In general, a standardized speech-perception measure offers a consistent way to compare performance across test conditions. The quiet score provides a within-visit reference for interpreting performance in noise. Because the same participants were assessed across conditions and time points, the intended comparison is within participants rather than simply between unrelated groups. The registry record does not report endpoint estimates, variability, confidence intervals, or a test of the difference, so the size and precision of any observed contrast cannot be evaluated from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes the study question and measurement procedure, but it does not report numerical results for the primary endpoint. There are no posted mean scores, standard deviations, estimated differences, confidence intervals, or p-values in the registry record for this analysis. As a result, the direction, magnitude, and statistical precision of the speech-perception contrast cannot be characterized.
The endpoint was defined as the ClearVoice score minus the quiet score at each follow-up visit. The description indicates that two sentence-list scores were averaged for each condition at a visit. This tells readers what quantity was intended for analysis, but a definition is not an outcome result. No conclusion about whether scores were higher or lower in one condition, or how large any difference was, can be drawn from the registry record.
The randomized crossover structure is relevant to interpretation. In general, crossover studies can compare conditions within the same participant, which can account for stable differences between participants. However, results can also depend on order, period, or effects that carry from one period into the next. The registry record does not report whether these factors were assessed or how they were handled. The order of MEDIUM and HIGH differed between the two sequences, but sequence counts and sequence-specific results are not reported in the registry record.
Enrollment was 48, while the serious-adverse-event record lists 46 at risk in its single group. These figures describe different registry entries and should not be treated as proof that all enrolled participants contributed primary-outcome data, or as an explanation of the difference in counts. The number with complete endpoint data and the reasons for any unavailable observations are not reported in the registry record.
The record lists zero statistical analyses. It therefore does not give a sponsor analysis to interpret alongside the endpoint description. It also does not report the analysis population, the handling of missing observations, or estimates adjusted for the crossover structure. With no numerical endpoint results, there is no basis to assess precision, consistency across follow-up visits, or the extent to which findings might vary by setting or sequence. The appropriate reading is that the registry documents a planned measurement and schedule, but does not present results sufficient to estimate the observed speech-perception contrast.
9. Statistical Methods Explained
The primary outcome is continuous: it is expressed as a percentage of words scored correctly. The record specifies a mean as the summary parameter and standard deviation as the measure of dispersion. In general, a mean describes the average observed score, while a standard deviation describes how spread out individual scores are around that average. Neither a mean nor a standard deviation for the primary outcome is reported in the registry record.
What does the within-subject comparison mean?
The outcome description calls the design within subjects. Each participant was assessed at follow-up with ClearVoice enabled and in quiet, and the stated analysis quantity was the ClearVoice score minus the quiet score. In general, paired measurements retain the link between observations from the same person. This can be useful because participants may differ in their typical speech-perception scores. A paired analysis focuses on within-person contrasts rather than treating each condition as if it came from separate people.
The registry does not state which statistical test or model was used to analyze those contrasts. It does not report whether the two follow-up visits were analyzed separately, jointly, or through a model that accounted for repeated observations. The listed count of statistical analyses is zero, so there are no posted analysis results to clarify these choices.
Why does the crossover order matter?
The two sequences used the same settings in reverse order: MEDIUM followed by HIGH in one group, and HIGH followed by MEDIUM in the other. In general, a crossover design can compare conditions within participants, but interpretation may depend on whether outcomes change over time or whether one period influences the next. These are often described as period and carryover considerations. The registry record does not report a washout interval, an assessment of carryover, or a statistical adjustment for period or sequence. It is therefore not possible to determine how those considerations were addressed.
What would a confidence interval add?
In general, a confidence interval gives a range of values compatible with an estimate under the assumptions of the analysis. It communicates uncertainty about the estimated contrast, rather than only indicating whether a statistical test crossed a chosen threshold. No confidence interval or other measure of uncertainty for the primary endpoint is reported in the registry record. A p-value is also not reported, and no significance threshold for the primary analysis is stated.
The record identifies a mean and standard deviation as the outcome summary, but does not provide the actual summary values. It also does not report an estimate for the ClearVoice-minus-quiet difference. Without those statistics, precision and variability cannot be assessed. General statistical concepts can describe how such quantities would ordinarily be interpreted, but they cannot replace absent results.
How should the sample-size illustration be read?
General planning illustrations based on an observed effect are not the same as the trial's original sample-size justification. The registry record says the illustration assumptions use a two-sided significance level of 0.05, equal allocation, a normal approximation, and a stated fraction of the observed effect. It also specifies that non-time-to-event planning counts are expressed as participants per arm. These assumptions describe a planning exercise, not observed power or evidence that the study was designed around a particular effect.
The observed primary-outcome effect and any calculated planning counts are not reported in the registry record. The record also does not report a sample-size justification for the trial itself. Consequently, no conclusion about whether the enrollment target was adequate for the endpoint can be drawn from the listed planning assumptions. In general, a planning calculation depends on the effect size and variability assumptions used, and should not be interpreted as a measure of the probability that a completed study has demonstrated an effect.
10. Multiplicity, Missing Data and Analysis Populations
The registry record identifies a primary outcome and a secondary outcome concerning AzBio sentences administered in recorded format in multi-talker babble. It lists two outcome measures in total, but does not report results for those measures. The record does not describe a plan for controlling the chance of false-positive findings when multiple outcomes, visits, or comparisons are considered. Such a plan is not reported in the registry record.
Several possible contrasts are described or implied by the measurement schedule: ClearVoice scores versus quiet scores, measurements at the two-week and four-week visits, and use of MEDIUM and HIGH settings in different sequences. The record does not state which contrast was designated as the principal statistical test beyond describing the ClearVoice-minus-quiet difference, or how multiple comparisons were handled. The analysis results and any multiplicity adjustment are not reported in the registry record.
The enrollment count is 48, but the number included in the primary endpoint analysis is not reported in the registry record. The record does not say how many participants posted measurements at both visits, whether any observations were missing, or how missing scores were handled. It also does not define an analysis population, such as an intention-to-treat or per-protocol population. Those details are important in a crossover study because incomplete participation in one period may affect which within-participant comparisons are available.
In general, missing-data methods can influence estimates if the participants with recorded outcomes differ from those without them. No missing-data method, sensitivity analysis, or account of withdrawals is reported in the registry record. Without these details and numerical results, readers cannot assess whether missing observations or multiple comparisons may have affected the reported evidence.
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 |
|---|---|---|---|
| Group 1 | 0 | 46 | 0.0% |
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 |
|---|---|
| Group 1 | 0 of 46 |
The registry's adverse-event entry lists one group, labeled Group 1, with 46 participants at risk. It reports zero participants affected by serious adverse events and zero participants affected by other adverse events in that entry. The death count is null, so a death count is not reported in the registry record. No serious adverse-event terms are listed.
These figures should be read as the counts in the registry's adverse-event entry, not as a comparison between ClearVoice MEDIUM and HIGH. The entry does not provide separate safety counts by randomized sequence or by setting. It also does not explain why the at-risk count is 46 while total enrollment is 48, and the reason for that difference is not reported in the registry record.
In general, a zero count in a registry entry means no events were recorded in that entry; it does not establish that the risk is absent. The adverse-event figures also do not give additional detail about collection methods, observation windows, or event ascertainment. Those details are not reported in the registry record. The safety counts should therefore be kept distinct from the unreported primary speech-perception results and should not be used to infer a treatment effect.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, unmasked crossover study was conducted, describes its two treatment sequences, and specifies a speech-perception measurement at two follow-up visits. It also defines the primary comparison as the score with ClearVoice enabled minus the score in quiet. These details identify what the study set out to measure and how the conditions were arranged.
The record does not provide numerical primary-outcome results. It therefore does not show the observed scores, the size or direction of the ClearVoice-versus-quiet contrast, or its statistical precision. No p-value, confidence interval, or analysis result is reported. The registry information cannot establish whether the measured differences were small or large, consistent or variable, or statistically distinguishable from no difference.
In general, a study design and an outcome definition are not substitutes for findings. Likewise, enrollment and a schedule of assessments do not establish that all participants completed all measurements. The number analyzed and the handling of incomplete observations are not reported in the registry record.
The randomized order of MEDIUM and HIGH offers a structure for examining the settings in a crossover arrangement, while the quiet measurements provide a within-visit reference. But the registry does not give setting-specific estimates, sequence-specific results, or details of how order and period were addressed. It is not possible to infer which setting had a higher score or whether any observed contrast would apply beyond the recorded study conditions.
The defensible interpretation is limited to the documented design and the absence of posted numerical outcome findings. The record does not support a conclusion about the magnitude, precision, or clinical importance of the primary endpoint.
13. Why This Trial Matters Statistically
This study illustrates why registry design details and numerical results answer different statistical questions. The record describes a randomized crossover schedule and a within-participant endpoint, but does not report the estimated contrasts or their uncertainty. Knowing how an outcome was defined is necessary for interpretation, but it is not enough to determine what the observed data showed.
The crossover structure is statistically notable because participants experienced both ClearVoice settings in different orders, with quiet measurements used as a reference. In general, this design can make within-person comparisons informative. At the same time, interpretation requires attention to time, sequence, and possible effects carried between periods. The registry record does not report how those issues were examined, which makes the analysis difficult to evaluate.
The record also separates the existence of a study from the availability of its results. It lists 48 enrolled participants and identifies the outcome schedule, yet lists zero statistical analyses and does not report primary-outcome estimates. This makes clear that readers should distinguish an endpoint description from evidence about the endpoint.
For biostatisticians and clinical researchers, the case highlights the importance of reporting the analysis population, missing-data handling, outcome estimates, and measures of precision. Those details allow readers to assess not only the direction of an estimate, but also how uncertain it is and how the design was reflected in the analysis. In this record, those elements are not reported, so the statistical value lies mainly in understanding the intended comparison and recognizing the limits of what can be inferred.
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 principal limitation for statistical interpretation is that numerical primary-outcome findings are not reported in the registry record. The means, standard deviations, ClearVoice-minus-quiet differences, confidence intervals, and p-values are all absent. The record also lists zero statistical analyses, leaving no analysis output to evaluate.
The registry describes randomized sequences and follow-up at two weeks and four weeks, but does not give the number assigned to each sequence or the number with outcome data at each visit. Completion by period, withdrawals, and reasons for missing observations are not reported in the registry record. The relationship between the enrollment count of 48 and the safety entry's 46 participants at risk is also not explained.
Important analysis details are not reported in the registry record, including the statistical model or test, the analysis population, handling of repeated measurements, and whether period, sequence, or carryover considerations were addressed. It is also not stated how multiple outcomes or visit-specific comparisons were handled.
The study is listed as unmasked. The registry record does not provide further information about how the speech tests were administered or scored with respect to masking. Population characteristics beyond the description of adults using the specified sound processing are not reported in the registry record, which limits assessment of how broadly the findings might apply even if results were available.
These limitations do not establish that the study was conducted incorrectly. They describe what cannot be assessed from the registry information: the magnitude and precision of the endpoint, completeness of the analysis, and the extent to which the crossover design was incorporated into the statistical methods.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: ClearVoice Sound-processing Strategy for AB HiRes 120 Cochlear Implant Users — NCT01066780.
- Registry record last updated 2020-07-22; status last verified 2012-10.
- Results first posted 2012-10-25.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record describes a completed, randomized, unmasked crossover study of ClearVoice in adults using HiResolution Fidelity 120 sound processing. It lists 48 participants enrolled and two sequences: MEDIUM followed by HIGH, or HIGH followed by MEDIUM, with each setting used for two weeks.
The primary outcome was percentage of words scored correctly on AzBio sentences in speech-spectrum noise. Scores with ClearVoice enabled were compared with quiet scores at two-week and four-week follow-up visits; the described analysis quantity was ClearVoice score minus quiet score. Numerical primary-outcome results and statistical analyses are not reported in the registry record.
The adverse-event entry lists 46 at risk, zero serious adverse events, and zero other adverse events in its single group. A death count is not reported in the registry record.