The Japanese Version of the Functional Listening Index-Paediatric (FLI-P(J)): Translation, Normative Data, and Clinical Feasibility.

Background

The Functional Listening Index-Paediatric (FLI-P) tracks functional listening development from birth to six years but lacks Japanese-language norms. This study translated the FLI-P into Japanese (FLI-P(J)) to generate normative developmental trajectories for typically hearing children.

Methods

Following translation, the FLI-P(J) was administered as an online caregiver survey in Japan. After applying sequential exclusion criteria (removing developmental concerns, zero scores, and IQR outliers) to 2976 responses, a normative sample of 2512 typically hearing children (2-73 months) was retained. Four parameter logistic functions were fitted to empirical percentile trajectories (5th-95th).

Results

FLI-P(J) scores demonstrated rapid growth across the first three years before gradually plateauing. Phase-level acquisition curves confirmed the expected developmental ordering. Most clinically flagged children scored at or below the 5th percentile.

Conclusions

This study establishes the first Japanese normative reference curves for functional listening. This cross-linguistic alignment, together with preliminary evidence that clinically flagged children scored at the low end of the distribution, supports the potential of the FLI-P(J) as a clinical benchmark for evaluating Japanese children who are deaf or hard of hearing, pending further validation in independently confirmed clinical samples.