The effect of an earphone’s Audio Transparency function on localisation in a simulated train station environment

Abstract

Background: Occurrences of pedestrian death and headphone use have led to investigation of the detrimental effect of headphones on sound localisation. New technology may reduce this undesirable effect. The current study explored the ‘Audio Transparency’ function on Bragi’s Dash earphones to determine if it would improve localisation. Participants: Fifteen normal hearing females and 6 normal hearing males (mean age=25 years) were recruited via word of mouth and social media. Methods: Participants were seated at the centre of a 12-speaker array where the auditory environment simulated a train station. Participants localised to car horn stimuli over three conditions: no earphones, Audio Transparency on, and Audio Transparency off. Real Ear Measurements (REMs) were obtained, and a subjective questionnaire completed. Results: Poorer localisation was obtained when the Dash was inserted, with worst performance overall when Audio Transparency was on. REMs identified most sound arrived at the eardrum with no earphones, and the least sound arrived with Audio Transparency off. A 9-point Likert scale showed an overall preference for clarity, ease of listening and sound quality in the no earphone condition. There was no significant difference for loudness between conditions, and no significant difference between earphone conditions for these categories. Conclusion: These results confirm the negative affect of earphones on localisation for normal hearers. The Audio Transparency function did not improve localisation, suggesting this feature may have limited benefit in improving pedestrian safety.