Development and Psychometric Evaluation of Mongolian Monosyllabic words for Word Recognition Testing

Objective: To develop a set of Mongolian monosyllabic word lists suitable for measuring Word Recognition Scores (WRS) and to evaluate their validity using psychometric function analysis. Methods: In the first phase, 220 Mongolian monosyllabic words that are widely recognized and commonly used in daily conversations by the general population were selected from various linguistic sources and phonemically balanced. A professional female voice artist digitally recorded these words in a sound studio, and their intensity levels were normalized using the Root Mean Square (RMS) value at 1000 Hz. In the second phase, word recognition tests were administered to 50 participants with normal hearing, aged 18 to 29 years. The tests took place in a sound-treated booth, with words presented at intensity levels ranging from –4 to 18 dB HL in 2 dB steps. The 220 words were randomly divided into four blocks of 55 words each. In the third phase, psychometric functions were generated using logistic regression analysis. To determine statistical differences between the lists and half-lists, chi-square (χ²) tests and one-way analysis of variance (ANOVA) were used. Results: From the original pool of 220 words, the 200 most perceptible monosyllabic words were selected based on recognition accuracy across presentation levels. These were divided into four balanced 50-word lists and eight 25-word half-lists. Psychometric functions were calculated for each list using logistic regression. The average slope at the 50% threshold was 10.43%/dB, and the slopes between 20% and 80% recognition ranged from 8.61 to 9.38%/dB. Statistical analyses showed no significant differences in recognition scores or intensity levels across lists and half-lists, confirming their equivalence. Intensity adjustments (≤ ±0.3 dB) were applied to standardize the 50% threshold across all lists (mean=6.16 dB HL). The results demonstrate that the developed Mongolian monosyllabic lists are phonetically and perceptually homogeneous, making them suitable for clinical and research use. Conclusions: This study developed a standardized set of Mongolian monosyllabic word lists with consistent psychometric properties. These materials are suitable for use by otologists and audiologists in clinical assessments and speech audiometry research in Mongolia.