Effect of Music Intervention on Infants' Brainstem Encoding of Speech: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effect of Music Intervention on Infants' Brainstem Encoding of Speech (NCT04509739), a na na study. The primary outcome is FFR-stimulus-f0 Correlation.

2. Clinical Question

The scientific question concerns whether infants’ frequency-following response (FFR), an auditory brainstem response to sound, reflects speech-signal encoding around the period of a music intervention. The primary measure compares the fundamental frequency extracted from a stimulus with the fundamental frequency extracted from the FFR. The registry description treats correlation in either direction as better than no correlation.

Because the study is single-group, the record does not set out a comparison between infants assigned to music intervention and infants assigned to a control condition. A pre-intervention and post-intervention assessment can describe change over time in the participants measured, but without a concurrent comparator it cannot by itself distinguish intervention-related change from other changes over time. The registry record does not report the result of the primary measure, so the stated question cannot be answered from the posted results.

3. Trial Design

The registry record identifies a behavioral intervention, a single-group model, no masking, and allocation listed as NA. It describes the study as an evaluation of infants’ FFR to a nonnative lexical tone before and after music intervention. The intervention was planned to start at 9 mo of age and consist of 12 sessions in a controlled laboratory setting. Its stated aim was to synchronize infants’ movements with musical beats through social and multimodal musical activities.

The record describes assessment at 7 mo and 11 mo of age, and states that the primary outcome was taken within 2 weeks following the last intervention session. These timing descriptions are reported as written; further details about scheduling or the timing of each assessment are not reported in the registry record. The intervention description also does not give a complete account of session procedures.

The record lists enrollment as 17. That figure does not establish how many participants completed the intervention, contributed an outcome measurement, or were included in an analysis. The safety information uses a denominator of 16, which is not the same denominator as the listed enrollment; the reason for that difference is not reported in the registry record.

The study status is terminated. The registry record gives a start date of 2019-10-16 and a primary completion date of 2020-03-15, but the reason for termination is not reported in the registry record. No separate control arm or randomized allocation is described. As a result, the design can support a description of measurements within the intervention group if results are available, but it does not provide a concurrent between-group estimate of an intervention effect.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as FFR-stimulus-f0 Correlation, measured over The outcome measure was taken within 2 weeks following the completion of music intervention (i.e., the last intervention session).

The primary endpoint is titled FFR-stimulus-f0 correlation. It is a continuous measure expressed as a correlation coefficient, with the registry record describing values from -1 to 1. The coefficient compares the fundamental frequency, or f0, extracted from the sound stimulus with the f0 extracted from the infant’s frequency-following response. The record presents this measure as an index of how well the auditory brainstem encodes speech signals.

In general, a correlation describes the direction and strength of association between two sets of values. The endpoint description assigns 1 to perfect positive correlation, -1 to perfect negative correlation, and 0 to no correlation. For this study, the record states that correlation in either direction is considered better than non-correlation. Interpretation therefore depends on the study’s stated definition rather than assuming that only a positive coefficient is meaningful.

The outcome timeframe is within 2 weeks following completion of the intervention, identified as the last intervention session. The brief summary also describes pre-intervention and post-intervention assessment. The registry record lists the mean and standard deviation as the outcome summary, but it contains no reported mean, standard deviation, participant-level values, or analysis results. Thus, the endpoint’s intended meaning is described, while the observed level of the measure and its precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes a continuous primary outcome summarized as a mean and standard deviation. In general, a mean represents the arithmetic average of observed values, while a standard deviation describes how spread out those values are around the mean. A mean alone does not show the distribution of individual measurements, and a standard deviation is not the same as the uncertainty in the mean. The record contains no reported primary-outcome mean or standard deviation.

What does the correlation measure?

The FFR-stimulus-f0 correlation compares f0 values extracted from the sound stimulus with f0 values extracted from the FFR. In general, correlation quantifies how two measurements vary together. The registry’s endpoint description defines its scale from -1 to 1, with 0 representing no correlation. It explicitly treats correlation in either direction as better than non-correlation. This definition matters: an interpretation should not silently recast the measure as one where only positive values indicate better encoding.

A correlation coefficient is not, by itself, a measure of clinical benefit or a direct measure of a child’s later development. It is an index tied to the signal-processing definition in the record. The posted results do not include an observed coefficient, so its direction, magnitude, and variability cannot be assessed.

What would an estimate and confidence interval add?

In general, an estimate gives the value calculated from the observed data, while a confidence interval communicates uncertainty around that estimate under the statistical model. Wider intervals indicate less precision than narrower intervals, though precision alone does not establish the importance of a result. A confidence interval can also show which values remain compatible with the data. The registry record reports no estimate or confidence interval for the primary outcome.

A p-value, in general, measures how incompatible the observed data are with a specified null hypothesis under the assumptions of a statistical model. It does not give the probability that the null hypothesis is true, and it does not measure the size or practical importance of an effect. No p-value or inferential analysis is listed for this outcome in the registry record.

How does the design affect the comparison?

The record identifies a single-group study with no randomized comparison. In a before-and-after design, a within-participant change can be estimated if measurements are available at both times and the analysis accounts for their pairing. Paired measurements are generally statistically dependent because they come from the same participant. Treating them as independent observations can misrepresent uncertainty. The registry record does not report which analysis, if any, was used, and it lists zero analyses.

Without a concurrent control group, an observed pre-to-post change would not alone identify what would have happened without the intervention. General alternative explanations include development over time, exposure to the assessment itself, and other changes during follow-up. These are design considerations, not claims that any particular influence occurred in this study.

What role do planning assumptions play?

The record’s planning assumptions describe an illustration for a two-arm calculation using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. They describe the target effect as a stated fraction of an observed effect. The study itself is recorded as single-group, not as a two-arm randomized comparison. Such planning assumptions do not constitute observed results or observed power. No numerical planning output or observed effect is reported in the registry record.

In general, over-dispersion means that variability is greater than a model assumes. When present, it can make standard errors too small and confidence intervals too narrow if the model does not account for it. The registry record does not report an over-dispersion assessment, and the continuous correlation endpoint should not be assumed to have been analyzed using a count model.

More broadly, a statistical method cannot be evaluated fully without knowing the analysis population, handling of repeated measurements, missing-data approach, and model assumptions. These details are not reported in the registry record. Since no primary-outcome analysis is listed, there is no reported method or result to assess for fit, precision, or robustness.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Music Intervention")
n   <- c(15)
m   <- c(0.048)
sp  <- c(0.331)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Music Intervention  15  0.048  0.331  -0.135  0.231

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and zero analyses. It does not report a multiplicity adjustment or explain whether additional outcomes, time points, or analyses were planned. The number of outcomes listed does not by itself establish how many comparisons were considered in the study. The approach to multiplicity is not reported in the registry record.

Missing data are important in a study that describes assessments before and after an intervention. If some participants lack one or both measurements, the available observations may not represent all enrolled participants. In general, methods for incomplete data depend on why measurements are missing and on the assumptions used in the analysis. The registry record does not report how missing primary-outcome measurements were handled, whether any were missing, or whether participants were excluded from an analysis.

The analysis population is also not reported in the registry record. The listed enrollment of 17 does not identify the number who completed the intervention or contributed a primary-outcome measurement. The safety record’s denominator of 16 should not be treated as the primary-outcome analysis population, because the record does not state that it is.

In general, an analysis population should be defined clearly so readers can understand which participants contribute to an estimate. For a repeated-measure study, it is also useful to know whether the analysis included participants with only one assessment or required measurements at both times. None of these details is reported in the registry record. With no posted outcome analysis, the influence of missing data, participant exclusions, or multiple testing cannot be evaluated.

12. 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 the Music Intervention group with 16 participants at risk for serious adverse events and 0 affected. It also lists 16 at risk for other adverse events and 0 affected, with 0 deaths. These counts describe the safety information in the registry record; they do not supply information about the primary FFR outcome.

A count of zero recorded events among participants at risk is not evidence that the possibility of an event is absent. In general, observed event counts depend on the number of participants monitored, the observation period, event definitions, and completeness of reporting. The record does not give additional detail about safety monitoring duration or event-collection procedures.

The listed enrollment is 17, whereas the safety denominator is 16. The reason for the different counts is not reported in the registry record. The safety denominator should therefore be read as the number listed at risk in the adverse-event entry, not as a substitute for the enrollment figure or an assumed outcome-analysis sample size. No serious adverse-event terms are listed.

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

The registry record establishes that a study was planned around a music intervention and an auditory brainstem encoding measure in infants. It describes the intervention as 12 sessions beginning at 9 mo of age and identifies the FFR-stimulus-f0 correlation as the primary endpoint. It does not provide the observed endpoint value or an analysis comparing assessments.

Accordingly, the posted results do not show whether the correlation changed, in which direction it may have changed, or how precisely any change was estimated. The record also does not report a comparison group. Even if a before-and-after estimate were available, a single-group change would not by itself establish that the intervention caused the change. General influences associated with age, repeated testing, and other events over time would remain relevant considerations.

The endpoint is a measure of the relationship between stimulus and FFR frequency information. It is not, on its own, evidence of a change in language development, learning, or another clinical outcome. The registry record does not report such outcomes or a link between the primary measure and later development.

The termination status is recorded, but its reason and its implications for data collection are not reported in the registry record. Enrollment is listed as 17, while the safety denominator is 16; neither figure establishes the number of participants with complete primary outcome data. These gaps limit what can be inferred from the record.

The appropriate interpretation is therefore descriptive: the registry identifies the research question, intervention, design, and intended measure, but it does not post results that answer the primary question. No conclusion about an intervention effect or its precision can be drawn from the information recorded.

14. Why This Trial Matters Statistically

This study illustrates why a clearly defined endpoint and a study design must be considered together. The FFR-stimulus-f0 correlation has a stated signal-based interpretation, and the registry record identifies when the primary outcome was intended to be measured. Those details clarify what the study sought to assess, even though no outcome result is listed.

The single-group design is statistically important because it shapes the kind of conclusion a study can support. Repeated measurements may describe within-group patterns, but without a concurrent comparison group they cannot alone separate intervention-associated change from other changes over time. This distinction is central when interpreting developmental measurements made at different ages.

The record also shows why enrollment, safety denominators, and analysis populations should not be treated as interchangeable. Enrollment is listed as 17, while the safety entry lists 16 at risk. The number contributing to the primary endpoint is not reported in the registry record. Readers need that distinction to judge the basis and precision of any estimate.

Finally, a defined outcome is not the same as a reported finding. The registry describes the measure and the intended timeframe, but lists zero analyses and no outcome values. Statistical interpretation depends on estimates and uncertainty as well as on the design; without those results, the research question remains unanswered in the posted record.

15. 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 main limitation for interpretation is the absence of posted primary-outcome results. The registry record lists one outcome measure and zero analyses, with no reported mean, standard deviation, estimate, confidence interval, or p-value. The effect’s direction, magnitude, and precision therefore cannot be evaluated.

The single-group design has no described concurrent control and no randomized allocation. This limits causal interpretation of any within-group change. The registry record does not describe an analysis that would address time-related changes or other alternative explanations.

The record lists enrollment as 17, but does not report the number completing the intervention or contributing primary endpoint data. The safety denominator is 16, and the reason for the difference is not reported in the registry record. The analysis population and missing-data handling are also not reported.

The study is marked terminated, but the reason for termination and its effect on recruitment, intervention delivery, or outcome collection are not reported in the registry record. The intervention’s detailed session procedures are not fully described in the arm description. The record does not report the statistical analysis plan, multiplicity approach, or any model diagnostics. These limitations leave substantial uncertainty about implementation and analysis, in addition to the absence of outcome findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Effect of Music Intervention on Infants' Brainstem Encoding of Speech — NCT04509739.
• Registry record last updated 2022-05-17; status last verified 2022-05.
• Results first posted 2022-05-17.
• 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.

19. Record Summary

The registry record describes a behavioral music intervention study of infants’ auditory brainstem encoding of speech. It lists a single-group design, no masking, enrollment of 17, and a terminated status. The intervention was planned to begin at 9 mo of age and include 12 sessions.

The primary outcome is the FFR-stimulus-f0 correlation, described as a continuous measure summarized by a mean and standard deviation and assessed within 2 weeks after the last intervention session. The record lists one outcome measure and zero analyses. No primary outcome results, analysis population, or missing-data method are reported in the registry record.

The safety entry lists 16 participants at risk, 0 serious adverse events, 0 other adverse events, and 0 deaths. The reason the safety denominator differs from enrollment is not reported in the registry record.