Directionality in BiCROS hearing aids: an investigation of objective and subjective outcomes.

Objectives: To assess the effect of forward and omnidirectional microphone configurations in BiCROS versus monaural hearing aids on objective and subjective outcomes in different noise conditions.

Design: After fitting and a 4-week acclimatisation period, speech recognition and sound quality were measured using forward directional, omnidirectional, and unaided settings. Two noise configurations were used, surrounding noise and noise presented from the aided (better) ear. Subjective outcomes were assessed using the SSQ-b and BBSS questionnaires and participant interviews.

Study sample: Eighteen adult participants (mean: 74.6 y; range: 61-94 y; ten males, eight females) with mild to moderately severe SNHL in their better ear (PTA0.5-4khz > 20 dB HL) and limited usable hearing in their poorer ear (average PTA0.5-4khz > 100 dB HL).

Results: Significant improvement in speech recognition and sound quality for BiCROS and monaural directional settings over omnidirectional and unaided, in both noise configurations. There were no significant differences observed between monoaural and BiCROS directional settings.

Conclusion: Speech in noise recognition and sound quality scores demonstrated a significant directional benefit for both BiCROS and monaural directional fitting settings over omnidirectional and unaided conditions. Unique BiCROS-specific experiences were identified in a patient-oriented approach. These can inform the development of BiCROS-tailored tools.