The study analyzes the separate evaluation of the results obtained from auditory, linguistic, and instrumental analyses applied in forensic phonoscopic examination and identifies the limitations of the existing “Y” probability scale. In order to generalize the results of complex research within a unified mathematical model, a new probability scale termed “X” is proposed, which is constructed based on the theory of mathematical probability. The numerical mean of the results obtained through different analytical methods is calculated. The conducted analysis demonstrates that the proposed probability scale enables an objective and measurable assessment of the results of complex studies. The new approach reduces subjectivity in the final expert conclusion, enhances the level of scientific justification of the findings, and provides a more reliable methodological basis for the practical application of forensic phonoscopic examination.