RP309 - Aging with a Traumatic Brain Injury: Implications for Auditory Processing and Listening Effort

Abstract:
Age-related hearing loss (ARHL) and traumatic brain injury (TBI) are extremely common among older adults (OAs). The present study examined the impact of ARHL and a history of TBI on binaural processing and listening effort. Middle-aged and OAs with a TBI were compared to age-matched controls on measures of listening effort, speech-in-noise, dichotic word recognition, and binaural release from masking.

Summary:
The objective was to evaluate the impact of traumatic brain injury (TBI) on binaural processing and listening effort in older adults (OAs) with age-related hearing loss (ARHL).

Rationale
ARHL results in a systematic decline in auditory processing and quality of life. Further, OAs with ARHL experience greater listening effort compared to younger control groups. For OAs, a TBI may exacerbate the negative impact of ARHL on auditory processing and listening effort. TBI affects up to 5.3 million people in the US, including OAs who experience higher morbidity, slower recovery, and poorer psychosocial outcomes relative to younger adults. Research shows that adults with TBI experience substantial hearing difficulty, auditory processing deficits, and listening effort, particularly in acoustically complex environments, long after initial injury recovery. There is a gap in knowledge regarding the impact of TBI on subjective hearing difficulty, auditory processing, and listening effort for OAs with ARHL. Given that ARHL and TBI independently negatively impact auditory processing, they may have a synergistic negative effect for OAs who experience both.

Design
Four groups participated: 1) middle-aged adults without TBI, 2) middle-aged adults with TBI, 3) OAs without TBI, and 4) OAs with TBI. The middle-aged adults had normal pure-tone thresholds (≤ 25 dB HL 250-4000 Hz and ≤30 dB HL at 8000 Hz). The OAs had no more than a moderately-severe high frequency sensorineural hearing loss (thresholds ≤70 dB HL at 4000 Hz). Inclusion criteria included symmetric hearing, right handedness, and a passing score on the Montreal Cognitive Assessment. A positive history of TBI was based on participant self-report.

Self-perceived hearing difficulties were assessed with the Hearing Handicap Inventory for Adults or Elderly and the Adult Auditory Performance Scale. Binaural processing was measured behaviorally with: 1) the Listening in Spatialized Noise – Sentences test (LiSN-S); 2) dichotic word recognition (DWR); and 3) the 500-Hz masking level difference. Listening effort was measured with the National Aeronautics Space Agency Task Load Index (NASA-TLX), a visual analog rating scale that assesses the perception of task demand.

Results
Middle-aged and OAs with TBI reported greater degrees of hearing difficulty (HHIA/E) than their age-matched controls. A composite binaural processing (CBP) score (average standardized z scores for the AAPS, LiSN-S, MLD, and dichotic word ear advantage) was calculated for each participant. Preliminary data analysis revealed that on average, OAs with TBI exhibited the poorest CBP score (0.73) as compared to OA controls (0.34), middle-aged TBI group (0.12), and middle-aged controls (-0.47). On average, listening effort (NASA-TLX) was greatest for the middle-aged and OA TBI groups compared to the age-matched control groups.

Conclusions
Middle-aged and OAs with a history of TBI exhibited greater hearing handicap, poorer binaural processing, and greater listening effort than their age-matched controls. OAs with TBI performed poorer than their age-matched control group, suggesting that a history of TBI exacerbated the negative impact of ARHL on binaural processing. Given the high prevalence of ARHL and TBI in the general population, a better understanding of the combined impact of both on OAs is needed.