Updating Disyllabic Word Lists for Italian Speech Audiometry

To describe a standardized clinical for Italian speech audiometry using new disyllabic word lists and to report preliminary validation and normative parameters in normal-hearing subjects.

In accordance with ISO 8253-3 guidelines, phonetically balanced disyllabic word lists were administered to 12 normal-hearing native Italian speakers (aged 18-25 years, pure-tone average ≤ 10 dB HL). Word Recognition Scores (WRS) were assessed across a descending intensity gradient (30-0 dB HL) to derive psychometric functions. Inter-list equivalence and 1-week test-retest reliability were evaluated in quiet and background noise (cocktail party noise). Reliability was quantified using intraclass correlation coefficients (ICC), Bland-Altman analysis, and repeated-measures ANOVA.

Mean speech recognition threshold (SRT50%) was 5.9 ± 2.2 dB HL, with a steep, highly sensitive average slope of 4.9%/dB near threshold. Maximum intelligibility (SRT 100%) was reached at 30 dB HL, across all lists. Intrasubject test-list variability was negligible (< 5% difference, ANOVA p > 0.05). Bland-Altman showed high temporal stability (mean bias: +0.88%; Limits of Agreement: ±1.5 words/list). Test-retest reliability was excellent (ICC = 0.957, 95% CI: 0.932-0.973, p < 0.001). In background noise, stable reproducibility was maintained, showing a well-contained coefficient of variation (14.5%-14.7%) at SNR 0 dB and a perfect ceiling effect at SNR +10. Good equivalence among lists were observed.

The new 10-item lists demonstrate robust equivalence and high test-retest reliability under ISO criteria. This validation workflow offers a time-efficient paradigm that is methodologically applicable to other languages, supporting standardized cross-linguistic clinical assessments.

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