Interaural Frequency and Loudness Mismatch in SSD CI Users: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Interaural Frequency and Loudness Mismatch in SSD CI Users (NCT05494632), a non-randomized na study. The primary outcome is Speech Understanding in Noise, Measured With the R-Space Test Environment. The R-Space Test Environment Simulates Speech Understanding in a Noisy Restaurant..

2. Clinical Question

The endpoint represents the signal-to-noise ratio associated with 50% speech understanding in a simulated noisy restaurant. Participants hear a sentence from the front while restaurant noise is played from loudspeakers around them; the noise level is adjusted according to whether their response is correct. The endpoint therefore focuses on speech perception under a defined listening challenge, rather than on a general measure of hearing or everyday function.

3. Trial Design

The registry lists a completed, non-randomized, single-group study with no masking. It describes three study periods addressing processor-program modifications in people with single-sided deafness who use a cochlear implant. The periods concern frequency mismatch in experienced recipients, frequency mismatch in newly implanted recipients, and loudness mismatch in experienced recipients. These are related questions, but they are not one randomized, like-for-like comparison across treatment arms.

In the first study, 20 experienced SSD-CI participants were assessed using their everyday program and a modified program intended to decrease interaural frequency mismatch. The second study involved 10 newly implanted participants assessed with the manufacturer’s default program and a modified program intended to decrease frequency mismatch. The third period concerned experienced recipients and a modified program intended to decrease interaural loudness mismatch. The safety record lists 15 participants at risk in that period. The primary-outcome population description is incomplete for this period, so the registry record does not report further enrollment detail there.

For each program, participants were tested in the R-Space twice. The record says testing occurred within a 2-3 month time period and after using each program for at least 6 weeks. This is a comparison of program conditions in the study population, not a comparison against a separately randomized control group. The record does not report the order in which program conditions were used or whether order was counterbalanced.

The listed overall enrollment is 45, and the study status is completed. The start date is 2022-08-12 and the primary completion date is 2024-07-30. A protocol-level account of the rationale for these design choices, including a sample-size justification, is not reported in the registry record. The record also does not report whether interim analyses were planned or conducted.

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: In Study 2, 5 participants used the default FAT for 6 weeks, then used the modified FAT for 6 weeks. 5 other participants used the modified FAT for 6 weeks, then the default FAT for 6 weeks. This was done to prevent order effects. Finally, all participants compared both FATs for 2 weeks. All 10 participants were tested twice with each FAT.

Overall Study

Analysis population for the primary outcome, as defined in the registry: 20 experienced SSD-CI participants were tested in the R-Space with their everyday use FAT and with the modified FAT (Study 1). Ten newly implanted SSD-CI participated in Study 2. The newly implanted group were tested in the R-Space with the manufacturer's default FAT and with a modified FAT. Fifteen experienced SSD-CI users were tested in the R-SPACE with their everyday program and with a modified loudness program (Study 3). Testing was done twice with each FAT or loudness program.

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: Participants in study 1 \& 2 were experienced SSD-CI users. Participants in study 2 were new SSD-CI recipients with no CI experience. Per study protocol, half began CI use with the default FAT and half with the modified FAT, switching FATs after 6 wks use \& finally comparing both FATs on the CI processor. Data of interest are results between the 2 FATs. Results of participants who used the default FAT 1st and those who used the modified FAT 1st are not of interest and therefore weren't analyzed.

6. Primary Endpoint

The registry lists the primary outcome as Speech Understanding in Noise, Measured With the R-Space Test Environment. The R-Space Test Environment Simulates Speech Understanding in a Noisy Restaurant., measured over Participants were tested in the R-Space twice with each speech processor program, e.g., everyday or default program and modified program. The testing was carried out within a 2-3 month time period, and after using each program for at least 6 weeks..

The primary endpoint is speech understanding in noise measured with the R-Space test environment. Its score is a signal-to-noise ratio in decibels (dB), defined in the record as the level associated with 50% speech understanding. The environment simulates listening in a noisy restaurant: restaurant noise comes from loudspeakers around the participant, a sentence is presented from the front, and the noise is adjusted in response to the participant’s answer.

The endpoint is relevant to the study’s stated aim because the program modifications were intended to reduce interaural mismatch, which the registry links to binaural processing cues and performance in noise. The test provides a controlled way to assess speech understanding under competing noise, rather than relying only on a participant’s general impression. The description states that a lower score represents better performance than a higher score and gives -5 dB SNR as the average score for participants with normal hearing. That reference value is contextual information, not a study result or a control-group outcome.

The registry identifies the summary parameter as the median and the dispersion measure as standard deviation. These describe different features of a set of scores: the median indicates its central position, while standard deviation describes variability around the mean. The record does not report the observed median or standard deviation for either program condition. Nor does it report a numerical contrast, confidence interval, or test result for the endpoint. As a result, the direction and precision of the study’s primary-outcome findings cannot be read from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The methods described in the registry focus on comparing speech-in-noise performance under two processor-program settings. The primary endpoint is summarized by a median and standard deviation, but the record does not provide the values. It also does not provide a numerical contrast or an uncertainty interval. The methods below explain how these statistical concepts are generally used; they do not identify analyses that the investigators performed unless the registry record says so.

What does the median describe?

General statistical context: the median is the central value after observations are ordered. It is less influenced by very high or very low observations than the mean, which can make it useful when a distribution is skewed or includes extreme values. A median alone does not describe the spread of the observations. The registry lists the median as the summary parameter, but does not state how the median was used in a comparison between program settings.

General statistical context: standard deviation describes dispersion around the mean, not around the median. A median paired with a standard deviation can be reported descriptively, but the reader should not assume that the standard deviation is an uncertainty measure for the median. The registry does not explain why this combination of summary statistics was selected or provide enough information to reconstruct the distribution of scores.

What does a signal-to-noise ratio score represent?

The R-Space score is a signal-to-noise ratio in dB associated with 50% speech understanding. The task adjusts noise according to whether the participant repeats a sentence correctly. As described in the record, a lower score represents better performance than a higher score. That direction is important: interpretation should follow the endpoint’s definition rather than assume that a larger number is necessarily better.

General statistical context: a score from an adaptive task is an estimate of performance under the test’s particular conditions. The score does not automatically represent performance in every real-world listening environment. The registry describes the R-Space as simulating a noisy restaurant, which gives the test a specific context. The record does not report evidence about how closely this score predicts performance in other settings.

How should a program comparison be understood?

Participants were tested using an everyday or default program and a modified program. The study is listed as single group and non-randomized. General statistical context: when observations come from the same participant under two conditions, a paired analysis can account for the fact that each person serves as their own reference. That differs from an analysis treating the conditions as independent groups. However, the registry record does not report whether the primary analysis used a paired method, how repeated tests were combined, or how within-participant correlation was handled. It would be inappropriate to assign a particular statistical test to the study based only on the testing description.

General statistical context: non-randomized comparisons can be affected by changes over time, differences in exposure to the conditions, and expectations related to the program being used. Lack of masking can also influence participant responses or test conduct. These are possible design considerations, not claims that such influences occurred in this study. The record does not report program order or whether order was balanced, so any assessment of order effects is not possible from the registry information.

What would an uncertainty interval add?

General statistical context: a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the analysis. For a program contrast, it can show a range of values compatible with the observed data and method. It is not a guarantee that the true value lies within that range, nor does it by itself establish whether a difference matters to participants. The registry record does not report a confidence interval for the primary endpoint, so precision cannot be assessed.

A p-value, if reported, would address how compatible the data are with a specified statistical null model under the test’s assumptions. It would not provide the size of a change or its practical relevance. The registry record does not report a p-value or identify the test used. No conclusion about statistical significance can be drawn from the endpoint description alone.

What does the planning illustration mean?

The registry describes planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. The record says that such figures are planning illustrations, not observed power. These assumptions describe a calculation framework and should not be mistaken for the trial’s original design rationale or for an analysis of the enrolled participants.

General statistical context: sample-size planning estimates how many participants per arm might be needed under chosen assumptions about the target effect, variability, allocation, and error rates. A planning estimate depends on those assumptions; it does not establish that a study had adequate power, and it cannot replace an observed effect estimate with uncertainty. The registry record does not report the trial’s own sample-size justification. The observed primary-outcome estimate needed to interpret a planning illustration is also not reported in the registry record.

The registry lists one outcome measure and one analysis. That listing does not disclose the full statistical analysis plan. The test, model, treatment of multiple observations per participant, missing-data rules, and analysis population are not reported in the registry record. These omissions limit independent evaluation of the analysis even apart from the absence of numerical endpoint results.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and one analysis. It does not report a multiplicity strategy, such as whether or how the analysis accounted for examining multiple study periods, program modifications, or other outcomes. The record’s listing of a single outcome measure does not establish that no additional analyses were planned or conducted. A correction for multiple comparisons, a hierarchy of hypotheses, or a prespecified primary contrast is not reported in the registry record.

The record also does not describe missing-data handling. It does not state whether all enrolled participants completed both program conditions, how incomplete R-Space testing was handled, or whether any observations were excluded. The analysis population and the number of participants contributing primary-outcome data are not reported in the registry record. Although the study enrollment and safety entries are listed, those entries do not establish the analysis denominator for the primary endpoint.

Repeated testing is part of the endpoint description: participants were tested in the R-Space twice with each program. The record does not say whether the two tests were averaged, analyzed separately, or combined in another way. Nor does it state whether the analysis accounted for correlation among observations from the same participant. These details affect how a program contrast and its uncertainty should be interpreted.

Without a reported multiplicity approach, missing-data method, analysis population, or numerical outcome result, it is not possible to assess whether the reported analysis—if any—followed a prespecified plan or how robust it would be to alternative choices. The registry record does not report those details.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The safety record lists three study periods. For Period 1: Study 1, 20 participants were at risk; serious adverse events, other adverse events, and deaths are each recorded as 0. For Period 2: Study 2, 10 participants were at risk; each of those three counts is 0. For Period 3: Study 3, 15 participants were at risk; each of those three counts is 0. The record lists no serious adverse-event terms.

These entries mean that the registry’s safety fields record no events in the reported categories for those periods. They do not show the outcome of the speech-in-noise endpoint, and they do not establish that the modified programs changed performance. The safety record does not report the event-collection window, definitions used, or whether the counts include all events regardless of relatedness. Those details are not reported in the registry record.

A zero count is a description of the recorded events, not proof that the underlying risk is zero. The interpretation also depends on how events were solicited and followed. Because the study is non-randomized and the safety entries are organized by study period, they should not be read as a randomized safety comparison between a modified program and a control treatment.

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

This study addresses a focused measurement question: whether speech understanding in noise differs when people with single-sided deafness and a cochlear implant use a modified processor program intended to reduce interaural frequency or loudness mismatch. The R-Space test provides a defined speech-in-noise task, and the registry describes testing with everyday or default and modified programs. These features make the clinical question understandable, but they do not supply an answer about the observed outcome.

The numerical primary results are not reported in the registry record. No outcome values, program contrast, confidence interval, or test result are available in the record. Consequently, it is not possible to say whether scores were better, worse, or similar under the modified program, or how precisely any difference was estimated. The endpoint’s stated direction—lower scores indicate better performance—does not reveal which condition had the lower score.

The study is recorded as completed, but completion status is not a result. The design is non-randomized, unmasked, and single group. It can describe performance under the tested program conditions, but the record does not document a randomized control comparison. That distinction matters when considering whether a difference could be attributed to the program modification rather than other influences.

The three periods also concern different groups and modifications: experienced recipients and newly implanted recipients in the frequency-mismatch studies, and experienced recipients in the loudness-mismatch study. The record does not report numerical results that would allow readers to examine these questions separately or together. An overall conclusion about all three periods would therefore go beyond the information recorded.

General statistical context: a result’s practical importance depends on the size and uncertainty of the estimated change, the measurement context, and what difference would matter to the population being studied. The registry does not report a threshold for a meaningful change. The normal-hearing reference in the endpoint description offers context for the test, but it is not a study control group and does not fill the gap in the missing outcome results.

13. Why This Trial Matters Statistically

The study is statistically notable for asking a focused question about an adjustable device program and a measurable listening outcome. It assesses speech understanding under a defined noisy condition rather than relying only on an unstructured report. Its endpoint description also makes the direction of the scale explicit: lower signal-to-noise ratio scores indicate better performance.

The design highlights a common distinction in clinical research: a within-participant comparison of settings is not the same as a randomized comparison between independent groups. Testing participants under everyday or default and modified programs can provide relevant information about performance across settings. At the same time, the non-randomized, unmasked, single-group design leaves important questions about condition order, expectation, and other time-related influences. The registry does not report the details needed to assess these possibilities.

The three study periods further show why results need to be reported by the question and population they address. Frequency mismatch and loudness mismatch are separate modification targets, and experienced recipients and newly implanted recipients are distinct study groups in the registry description. Without numerical findings for each period, readers cannot assess whether the result differs across those contexts or whether a combined summary would be justified.

The record also illustrates the importance of complete statistical reporting. A stated endpoint and an analysis count are not substitutes for the observed estimate, uncertainty, analysis method, and missing-data information. Those details allow readers to judge magnitude and precision and to understand how the analysis relates to the design. Here, the record identifies the planned measurement and reports safety counts, but does not report the numerical primary-outcome results or key analysis details. The completed status therefore cannot support an inference about the direction or size of the outcome.

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.

A central limitation of the registry record is that numerical primary-outcome results are not reported. The median and standard deviation for speech understanding in noise, a comparison between program settings, and measures of uncertainty are all absent. The record therefore does not allow readers to estimate the observed change or its precision.

The design is non-randomized, unmasked, and single group, and the registry cautions that the arms are not a like-for-like control comparison. The order of program use and any approach to balancing that order are not reported. The analysis method for repeated testing is also not reported, even though participants were tested twice with each program. These gaps make it difficult to evaluate potential order effects or the handling of within-participant observations.

The three periods address different mismatch targets and participant groups. The registry does not report period-specific primary results or enough information to assess whether a combined analysis was intended. The primary-outcome population description is incomplete for the loudness-mismatch study, ending after “Fifteen.” Further details about that group are not reported in the registry record.

The record does not report the statistical test, analysis population, missing-data procedures, multiplicity approach, or a sample-size justification. It also does not report a threshold for a clinically meaningful difference. The endpoint is measured in a simulated restaurant environment; the record does not report how well that test result corresponds to performance in other listening situations. These limitations concern the information available in the registry record and do not establish that unreported methods or results do not exist elsewhere.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Interaural Frequency and Loudness Mismatch in SSD CI Users — NCT05494632.
• Registry record last updated 2026-03-23; status last verified 2026-03.
• Results first posted 2025-07-01.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry record describes a completed, non-randomized, unmasked, single-group study of speech processor program modifications in people with single-sided deafness who use a cochlear implant. The three periods address reducing interaural frequency mismatch in experienced recipients, reducing frequency mismatch in newly implanted recipients, and reducing loudness mismatch in experienced recipients. Participants were assessed in the R-Space under everyday or default and modified program settings.

The primary endpoint is the median signal-to-noise ratio associated with 50% speech understanding, with standard deviation listed as the dispersion measure. The record does not report the numerical primary-outcome results, a comparison estimate, or an uncertainty measure. It lists one outcome measure and one analysis, but the analysis method and key details about missing data and analysis populations are not reported.

The safety entries record zero serious adverse events, zero other adverse events, and zero deaths in each of the three listed periods. The study status is completed. Completion and the safety counts do not supply the missing primary-outcome results.