Fig 1.
PRISMA flowchart of the study selection procedure.
Table 1.
Characteristics of all studies included in the meta-analysis, including outcome measurements, reported LAEP components and risk of bias.
Fig 2.
Calculation of the Standardized Mean Difference (SMD) for P300 latency.
Illustration to clarify the used procedure. Raw mean differences and within-study standard deviations were calculated based on the reported mean values and between-subject variations. SMDs were then calculated and used as input for the multivariate model. Grey lines represent control subjects and black lines represent tinnitus patients. Individual subjects are represented by dotted lines while the average response is presented as a solid line.
Fig 3.
Forest plot of the primary multivariate analysis.
Results are grouped according to LAEP component. Results from individual papers are presented as standardized mean differences (SMD) ± 95% confidence intervals. Overall results from the primary meta-analytic model are given for each component; diamonds represent SMD with 95% confidence intervals, while error bars correspond to credibility/prediction intervals, defined as the intervals where approximately 95% of the true outcomes are expected to fall.
Fig 4.
Forest plots for P300 amplitude (left) and latency (right) show no evidence for publication bias.
Fig 5.
Graphical overview of the effects of increasing age, hearing loss and tinnitus on the LAEP waveform.
Illustration produced with BioRender.