Background: Sound localization skills are essential in everyday life and contribute to the normal development of children. Since hearing loss can severely impact the ability to localize sounds and because of the sensitive nature of the development of the central auditory cortex, early intervention and testing are crucial. Despite this, sound localization is not routinely evaluated in clinic, and to date, there is no simple standardized test to assess sound localization accuracy in children.

Methods: Using a newly developed simple procedure using 9 loudspeakers set 22.5 degrees apart in the frontal field (Immersion 360° system), we assessed sound localization skills of 49 normal-hearing children aged 2.08-12.92 years old (y.o) and compared them to a group of 12 normal-hearing adults. This was done to obtain normative data to properly evaluate and followup hearing-impaired children across a wide age range.

Results: The overall response rate was 98% with 84.68% of accurate responses (PAR). There was a statistically significant improvement in sound localization accuracy as measured by the root mean square of error (RMSE) between children aged 2-3 and participants aged 6+ (p<0.01). The RMSE as predicted by age followed an exponential fit decay model with an R 2=0.66, meaning that up to 66% of sound localization accuracy can be explained by age. Participants aged 2-3 years had the lowest accuracy (RMSE=19.81°±5.75°) and the highest percentage of incomplete tests (27%).

Conclusion: The test was effective to assess sound localization in both children and young adults. The results suggest development of sound localization starts at an early age and reaches a plateau between 5.5 and 9.1 years old. Children aged 2-3 had more difficulties responding suggesting specific adaptations could be made for that age group.