Vehicle noise: comparison of loudness ratings in the field and the laboratory

Objective: Distorted loudness perception is one of the main complaints of hearing aid users. Measuring loudness perception in the clinic as experienced in everyday listening situations is important for loudness-based hearing aid fitting. Little research has been done comparing loudness perception in the field and in the laboratory.Design: Participants rated the loudness in the field and in the laboratory of 36 driving actions. The field measurements were recorded with a 360 degrees camera and a tetrahedral microphone. The recorded stimuli, which are openly accessible, were presented in three conditions in the laboratory: 360 degrees video recordings with a head-mounted display, video recordings with a desktop monitor and audio-only.Study samples: Thirteen normal-hearing participants and 18 hearing-impaired participants with hearing aids.Results: The driving actions were rated as louder in the laboratory than in the field for the condition with a desktop monitor and for the audio-only condition. The less realistic a laboratory condition was, the more likely it was for a participant to rate a driving action as louder. The field-laboratory loudness differences were bigger for louder sounds.Conclusion: The results of this experiment indicate the importance of increasing realism and immersion when measuring loudness in the clinic.