title: The effects of simulated hearing loss on speech recognition and walking navigation.
abstract: OBJECTIVE
  The objective was to assess whether a concurrent but independent navigation task exacerbates the effects of hearing loss on speech recognition and whether hearing loss degrades performance of the navigation task during the concurrent but independent listening task.
  
  
  BACKGROUND
  Navigation performance and speech comprehension both decrease when a driver follows hard-to-hear concurrent verbal instructions. It remains unknown how much both tasks would be affected when performed concurrently, if tasks were independent.
  
  
  METHODS
  Participants performed a listening task by responding to Callsign Acquisition Test (CAT) stimuli at three simulated hearing levels. For each hearing level, one trial was performed with the participant standing still and another trial was performed while navigating a path in a virtual environment using a handheld map. In one more trial, participants navigated a path with no CAT. The proportion of call signs correctly repeated and the total time required to walk the path were measured.
  
  
  RESULTS
  CAT scores showed an expected negative effect of hearing loss. Concurrent navigation produced an even larger decrease in CAT score. Hearing loss caused a slight but not significant decrease in navigation task performance.
  
  
  CONCLUSIONS
  A person with hearing loss may communicate less effectively while walking than predicted on the basis of hearing loss alone. The hearing loss, however, does not significantly decrease walking performance in a simple navigation task.
  
  
  CONCLUSIONS
  Obtained results may guide soldier performance modeling and requirements for communication systems used during physical activity when a soldier's hearing becomes compromised during dismounted combat operations.
authors.affiliation: Perceptual Sciences Branch, Army Research Laboratory, 520 Mulberry Point Rd., Aberdeen Proving Ground, MD 21005-5425, USA.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Weatherless
authors.forename: Paul D
authors.initials: PD
authors.lastname: Fedele
authors.forename: Kathy L
authors.initials: KL
authors.lastname: Kehring
authors.forename: Tomasz R
authors.initials: TR
authors.lastname: Letowski
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D056344:Executive Function / Q000502:physiology; D005260:Female; D034381:Hearing Loss / Q000150:complications* / Q000523:psychology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013067:Speech Perception; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology; D016526:Workload; D055815:Young Adult