Investigating Stimulation Parameter and Electrode Mode Changes on Speech Perception in Experienced Adult Cochlear Implant Recipients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Investigating Stimulation Parameter and Electrode Mode Changes on Speech Perception in Experienced Adult Cochlear Implant Recipients (NCT06298396), a na na study. The primary outcome is Paired Mean Difference Score for CNC Words Correct Between Default and LP1 MAPs in Quiet.

2. Clinical Question

The study asks whether speech perception in quiet differs when experienced adult cochlear implant recipients use a default MAP or a low-power 1 (LP1) MAP. The primary comparison is within participants: each participant’s CNC word score under one program is paired with that participant’s score under the other. This differs from a comparison of separate treatment groups, because the same person contributes measurements under both conditions.

The record describes speech assessment using recorded CNC monosyllabic words and defines the score as a percentage of words correct. It also names other outcomes concerning LP1 versus LP2 and LP1 versus LP3, speech reception in noise, and switching acceptability. The numerical primary and secondary results are not reported in the registry record, so the direction and size of any observed differences cannot be described from the record.

3. Trial Design

The registry identifies this as a prospective, single-centre, within-subject investigation of stimulation parameter and electrode mode changes in experienced adult cochlear implant recipients. It lists the study as completed, with a start date of 2024-05-27 and a primary completion date of 2024-12-16. The sponsor is Cochlear, and the registered enrollment is 20.

The interventions listed are programs using the default MAP, LP1 MAP, LP2 MAP, and LP3 MAP. The arm description says participants would receive four different MAPs for use during two take-home periods and then complete hearing assessments using each MAP. This is a repeated-measures structure: outcomes under different programs are assessed in the same participant. The primary comparison specifically concerns the default and LP1 programs, while registered secondary outcomes include comparisons involving LP2 and LP3.

The record gives allocation as NA and describes a single-group model. It does not describe a randomized allocation between separate groups. The official title calls the investigation single-blinded, while the registry’s masking entry is NONE; the record does not explain this difference or specify who, if anyone, was blinded. The order of program use, duration of each take-home period, and procedures for managing order effects are not reported in the registry record.

The study is listed as phase NA. No sample-size justification, protocol-level statistical plan, or interim-analysis plan is reported in the registry record. The recorded design therefore supports describing the intended within-person comparisons, but not inferring details of allocation, blinding, or analysis that are not stated.

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.

Default MAP

Reasons for not completing this period:

Low Power 1 (LP1) MAP

Low Power 2 (LP2) MAP

Low Power 3 (LP3) MAP

Analysis population for the primary outcome, as defined in the registry: One participant had the default MAP created using a Pulse Width of 37 µs rather than the required 25 µs, so there were 19 paired data points for analysis. All remaining participants were tested with the Default and LP1 MAPs

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.

Population: All participants were assigned to be tested with each test MAP (LP1, LP2, LP3) and the baseline (Default).

6. Primary Endpoint

The registry lists the primary outcome as Paired Mean Difference Score for CNC Words Correct Between Default and LP1 MAPs in Quiet, measured over 10 participants completed this test at Week 4, and 10 participants completed this at week 8.

The primary endpoint is the paired mean difference in CNC words correct between the default and LP1 MAPs in quiet. CNC refers to recorded consonant-nucleus-consonant monosyllabic words. For each MAP, the registry says speech perception was assessed as the percentage of words answered correctly. The stated score range is 0% to 100%, with higher scores representing better performance on this measure.

A paired mean difference summarizes the average within-participant change between two conditions. Pairing is useful because each participant serves as their own reference: stable differences between people, such as a person’s generally higher or lower word score, are accounted for in the within-person comparison rather than being mixed into a comparison of unrelated groups. It does not, by itself, remove effects of test order, learning, or other changes between assessments.

The registry says an average CNC word score for each MAP was calculated by combining data from the specified timepoints. The timeframe description states that 10 participants completed this test at Week 4 and 10 participants completed it at week 8. One participant had a default MAP created with a Pulse Width of 37 µs rather than the required 25 µs, leaving 19 paired data points for analysis. The numerical mean difference and its 95% confidence interval are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary outcome as a mean of a continuous measure and gives a 95% confidence interval as its dispersion measure. The planned contrast is paired, because the default and LP1 scores come from assessment of the same recipients. The numerical estimate and interval themselves are not reported in the registry record.

Why use a paired comparison?

General statistical explanation: when two measurements are made on the same person, the analysis can focus on the within-person difference. Each participant’s pair is compared before those differences are averaged. This often makes the comparison more informative than treating the two sets of scores as if they came from unrelated people, because between-person variation is not the target contrast. Pairing depends on correctly matching each person’s measurements across conditions. It does not guarantee that every participant has the same response, and a mean can conceal variation in the direction or size of individual differences.

The registry states that there were 19 paired data points for the primary analysis after one participant’s default MAP was created with a Pulse Width of 37 µs instead of the required 25 µs. It does not report the paired values, their distribution, or whether the analysis used a particular model beyond the paired mean difference. Details such as a normality assessment, robust analysis, or sensitivity analysis are not reported in the registry record.

What does the confidence interval contribute?

General statistical explanation: a confidence interval conveys the precision of an estimated effect, not just its point estimate. The interval’s interpretation depends on the sampling and analysis assumptions. For a paired mean difference, uncertainty is related to the variability of the within-person differences and the amount of paired information. A confidence interval does not show the range of outcomes for individual participants. The record specifies a 95% confidence interval but does not report its endpoints, so its precision cannot be assessed.

How should the score scale be understood?

The endpoint is percentage of recorded CNC monosyllabic words answered correctly, with a stated minimum of 0% and maximum of 100%. This bounded scale places an upper and lower limit on possible scores. General statistical explanation: when scores cluster near a scale limit, the pattern of variation may differ from that of an unbounded continuous measure. The registry record does not give baseline or condition-specific score distributions, so it is not possible to determine whether ceiling or floor effects were present. The paired mean difference remains interpretable in percentage-word-score units, but its distribution and context matter when assessing its precision and relevance.

What do the planning assumptions mean?

The record describes a sample-size 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. It says the effect to detect is a stated fraction of the observed effect. These are planning assumptions, not evidence of the study’s original design rationale. The illustration’s equal-allocation, two-arm framing does not describe the registered single-group, within-subject structure. No numerical planning estimates or original sample-size justification are reported in the registry record. Any such planning illustration is not observed power and should not be treated as a result from participants.

What cannot be assessed from the record?

The record does not describe the precise statistical procedure used to form the primary confidence interval, how the timepoint scores were combined in practice, or whether other covariates were considered. It does not report an analysis plan for repeated measurements, order effects, or sensitivity checks. Those omissions limit reproducibility and make it inappropriate to infer model choices from the endpoint label alone.

10. Multiplicity, Missing Data and Analysis Populations

The investigation names a primary comparison and multiple secondary outcomes. The secondary outcomes include paired CNC word-score differences for LP1 versus LP2 and LP1 versus LP3 in quiet, paired speech-reception-threshold differences in noise for those comparisons, and a switching acceptability rating between LP2 and LP3. The registry lists 7 outcome measures and 6 analyses. It does not report how many hypotheses were tested in the final analysis or whether the reported analyses correspond to every registered measure.

Multiplicity arises when several outcomes or contrasts are examined. General statistical explanation: when many statistical tests are conducted, the chance of at least one apparently notable finding can increase unless the analysis plan accounts for the family of tests. Possible approaches include prespecifying a primary outcome, adjusting significance thresholds, or treating secondary analyses as exploratory. The registry record does not report whether any multiplicity adjustment or hierarchy was used. No result should be described as adjusted or unadjusted on the basis of this record.

For missing data, the primary population description says one participant was not included in the paired analysis because the default MAP had a Pulse Width of 37 µs rather than the required 25 µs; the record reports 19 paired data points. The timeframe says 10 participants completed the test at Week 4 and 10 participants completed it at week 8. The registry does not explain whether these timepoint counts reflect different participants, how incomplete assessments were handled, or whether missing values were imputed. It also does not report a broader intention-to-treat or per-protocol definition. The only analysis-population detail available is the stated count of paired data points and the reason given for excluding one participant’s pair.

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.

Most frequent non-serious adverse event terms

For the All Participants group, the registry reports 0 serious adverse events among 20 participants at risk. It reports 1 other adverse event among 20 participants at risk and 0 deaths. No serious adverse-event terms are listed.

These are registry counts, not estimates of comparative risk: the study is listed as a single-group investigation, and the record does not provide a separate control group for a like-for-like safety comparison. The counts do not establish whether an event was caused by a MAP or by study participation. The registry record does not provide a description of the other adverse event, its severity, timing, or relationship to the device or study procedures.

General statistical explanation: a count of zero observed events does not establish that an event is impossible or that its underlying rate is zero. Interpretation also depends on follow-up duration and completeness of adverse-event ascertainment, details not reported in the registry record. These figures should be read as the adverse-event counts recorded for this study, not as a guarantee about safety in other settings or participants.

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

The registry record establishes that the study was designed to assess speech perception under different MAP programs in experienced adult cochlear implant recipients. Its primary question concerns the paired mean difference in CNC words correct in quiet between the default and LP1 MAPs. The record also identifies additional comparisons involving LP2 and LP3, noise testing, and switching acceptability.

The record does not report the numerical primary outcome, its 95% confidence interval, or the numerical secondary outcomes. Consequently, it cannot show the direction or size of the primary difference, its precision, or whether the score pattern was consistent across participants. The endpoint description says higher CNC scores mean better performance on that test, but this alone does not establish which MAP produced higher scores. The subtraction convention for the paired contrast is not stated.

General statistical explanation: a difference in an assessment score is evidence about that measure under the conditions studied. It is not automatically evidence about every aspect of hearing, communication, or day-to-day experience. The registry record does not report a threshold for a clinically important CNC score difference, nor does it report how score differences relate to broader outcomes. It would therefore be inappropriate to label an unreported estimate as clinically meaningful or unimportant.

The within-subject design allows comparison of conditions within participants, but it does not itself establish that observed differences were caused only by the MAP setting. The record does not report the order of program use, detailed blinding procedures, or adjustments for possible order or period effects. These considerations limit what can be inferred even if numerical estimates are available elsewhere. The posted registry information supports a description of the study question and recorded methods; it does not support a claim that a particular program improves or worsens speech perception.

13. Why This Trial Matters Statistically

This study is statistically notable for using a within-subject comparison to examine multiple device programs in experienced adult cochlear implant recipients. With paired observations, the central statistical quantity is the difference within each participant, rather than the difference between unrelated group averages. That design choice directly matches the primary question about CNC word scores under the default and LP1 MAPs.

The registry also makes an analysis-population issue explicit: a default MAP created with a Pulse Width of 37 µs rather than the required 25 µs resulted in 19 paired data points for the primary analysis. Reporting this reason helps readers distinguish the stated paired analysis population from the enrollment figure. The record separately notes assessments at Week 4 and week 8, making clear that timing is part of the outcome description, although it does not explain how the timepoint counts relate to the paired set.

The study raises common interpretive issues for repeated-measures research: how to define the paired contrast, whether assessment order matters, how to handle more than one outcome, and how precisely the mean difference is estimated. Those questions cannot be resolved from labels alone; they depend on the analysis details and numerical results. The registry does not report those details for the primary statistical estimate.

Its value for statistical reading lies in the clear identification of the intended primary measure and the reported reason for excluding one pair. At the same time, the absent estimate, interval, multiplicity plan, and fuller missing-data description prevent assessment of the observed effect. The record is therefore useful for understanding the analytical question, while leaving the empirical result and its precision unreported.

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.

Several trial-specific limitations are apparent from the registry record. First, the numerical primary mean difference and 95% confidence interval are not reported, and numerical secondary results are also not reported. The magnitude, direction, and precision of the observed comparisons therefore cannot be assessed from this record.

Second, the record identifies 19 paired data points after one participant’s default MAP was created with a Pulse Width of 37 µs rather than the required 25 µs. It does not state whether excluding that pair was prespecified, whether alternative analyses were performed, or how the participant’s other measurements were handled. The timepoint description gives 10 participants at Week 4 and 10 at week 8, but does not clarify how those counts map to the paired analysis or describe other missing assessments.

Third, the registry does not report the order in which MAPs were used, whether the order was balanced, or how possible practice, carryover, or period effects were addressed. The official title describes the investigation as single-blinded, but the masking entry is NONE; who was blinded and how that designation was applied are not reported. These uncertainties constrain interpretation of within-person differences.

Finally, the registry does not report multiplicity procedures, a detailed statistical model, an analysis-population definition beyond the paired-data note, or a sample-size justification. The enrollment of 20 and the stated paired analysis population should not be read as evidence about precision without the outcome variability and estimated interval. Further participant characteristics and longer-term follow-up details are not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Investigating Stimulation Parameter and Electrode Mode Changes on Speech Perception in Experienced Adult Cochlear Implant Recipients — NCT06298396.
• Registry record last updated 2025-12-17; status last verified 2025-11.
• Results first posted 2025-12-17.
• 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.

18. Record Summary

The registry describes a completed, prospective, single-centre, within-subject investigation of stimulation parameters and electrode modes in experienced adult cochlear implant recipients. It lists enrollment of 20 and interventions using default, LP1, LP2, and LP3 MAPs. The primary outcome is the paired mean difference in CNC words correct between default and LP1 MAPs in quiet, reported with a 95% confidence interval as the intended dispersion measure.

The registry states that 19 paired data points were available for the primary analysis after one participant’s default MAP was created with a Pulse Width of 37 µs rather than the required 25 µs. It reports 10 participants completing the test at Week 4 and 10 at week 8. Serious adverse events and deaths were recorded for 0 participants, while 1 other adverse event was recorded among 20 at risk. The primary numerical result, its interval, multiplicity handling, and fuller missing-data methods are not reported in the registry record.