Use of non-individualized head-related transfer functions to measure spatial release from masking in children with normal hearing

Abstract

Spatial hearing studies with children have typically been conducted using loudspeakers in laboratories. However, loudspeaker arrays are rare in clinics due to high cost and technical set-up requirements. The use of virtual auditory space (VAS) with non-individualized head-related transfer functions (HRTFs) can increase the feasibility of assessing spatial hearing abilities in clinical settings. A novel paradigm for measuring spatial release from masking (SRM) was developed using non-individualized HRTFs. This paradigm measures the minimum angular separation needed between target and masker to achieve a 20% increase in target speech intelligibility. First, the 50% speech reception threshold (SRT) was measured with target and masker co-located to one side. Then, the masker position was adaptively changed to achieve 70.7% intelligibility while maintaining the signal-to-noise ratio at the level of the co-located SRT. To verify the use of non-individualized HRTFs, normal-hearing children were tested (1) using a loudspeaker array and (2) in headphone-based VAS created using KEMAR HRTFs measured in the same setup as (1). Preliminary results showed that co-located SRTs and target-masker angle separation to achieve a 20% SRM were similar in loudspeaker array and in headphone-based VAS. This suggests that non-individualized HRTFs might be used in an SRM task for clinical testing.