Listen Carefully: An Exploratory Study of the Association Between Listening Effort and Cognitive Function
Condition: Cognitive Impairment, Mild; Hearing Loss
MeSH terms: Hearing Loss; Cognitive Dysfunction
Study type: Interventional

Summary: 
      This study aims to investigate the association between listening effort and cognitive
      function for both cognitively healthy individuals and for patients with Mild Cognitive
      Impairment (MCI) in mid-to-late stages of life, and furthermore to investigate listening
      effort and cognitive function after several weeks of hearing aid use. Listening effort is
      measured by the recording of peak pupil dilation during a sentence-final word identification
      and recall (SWIR) test, cognitive performance is measured using a battery of pen and paper
      cognitive tests, and hearing loss is measured with pure tone audiometry (PTA). A select
      number of participants in both the cognitively healthy and MCI group will be administered
      hearing aids, and the study will re-test both listening effort and cognitive performance.
    

Detailed description: 
      This is an exploratory proof-of-concept study and an exploratory intervention study with
      hearing aids in the context of listening effort. With a case (MCI) and control group
      (cognitively healthy), investigators will examine the associations between listening effort
      and cognitive function and assess the effect of hearing aid use on both listening effort and
      cognitive function test scores for those without hearing impairment. There is not sufficient
      literature to support a sample size calculation for this association study. Investigators
      will recruit approximately 50 participants. Half of these participants (n=25) will be
      individuals who have been diagnosed with MCI, according to the Winblad criteria (ICD10), with
      a Mini Mental State Examination (MMSE) score ≤ 26. The control group of participants (n=25)
      will be cognitively healthy individuals. All participants will undergo both listening effort
      testing, coupled with pupillometry and cognitive performance testing, based on a battery of
      pen-and-paper neuropsychological tests.

      As investigators aim to measure cognitive effort exerted when listening and understanding
      speech in noise, is important that all study participants exhibit a normal sensitivity
      threshold within the ear canal. This will be assessed using Pure Tone Audiometry (PTA).

      Assessment scores for cognitive function will be recorded in a clinical setting, and will be
      based on a battery of pen-and-paper neuropsychological cognitive tests. The Stroop Test,
      Trail Making Test (part A & B), Symbol Digit Modalities Test (SDMT), Verbal Fluency Tests
      (category: animals and lexical), Rey Complex Figure Test and Logical Memory Test (Part A)
      will be administered.

      The objective measure of listening effort, pupil dilation, will be recorded as a measure of
      task performance accuracy and pupil dilation will be measured during a SWIR test, which is
      used to measure speech identification and recall in varying background noise. Prior to the
      SWIR test, participants undergo an adaptive Danish Hearing in Noise Test (HINT), comprising a
      list of equally intelligible sentences to be repeated in varying decibel (dB) levels of
      background noise to determine the individual's speech reception threshold (SRT) at 80%
      correct responses.

      During the SWIR test, the participant is fitted with PupilLabs' eye-tracking system, an open
      source system consisting of clip-in eye tracking hardware to be placed in a Virtual Reality
      (VR) headset. To prevent floor and ceiling effects that are independent to baseline pupil
      size, the illumination within the VR display is individually adapted to the individual's
      midpoint prior to data collection between dim (~30 lux) and bright (~230 lux), with an
      average illuminance of 110 lux. A software suite allows the capture and post-processing of
      the data feed, including pupil diameter. For the purpose of this study, the PupilLabs
      software is controlled via a MATLAB interface.

      Everyone who participates in Part 1 (listening effort testing and cognitive testing) will be
      invited to participate in Part 2 (hearing aids). It is not a requirement to participate in
      the administration, 6-week use, and re-testing procedures involved in Part 2 of the study.
      All cognitively healthy participants will be invited to participate, only MCI patients with a
      live-in informant will be given this opportunity. After ear measurement and dome and wire
      length selection, Oticon Opn S 1 miniRITE hearing aid fitting will occur wirelessly using
      Genie software, followed by hearing aid use instructions. The fitting will use Open domes,
      the second generation of the National Acoustic Laboratories (NAL) fitting protocol (NAL-NL2)
      and will increase gain seven steps on top of Real Ear Unaided Gain (REUG) from 750 Hz to 6
      kHz.
    

Intervention name(s): Oticon Opn S 1 miniRITE hearing aid
Intervention type(s): Device
Intervention description(s): Everyone who participates in Part 1 (listening effort testing and cognitive testing) will be invited to participate in Part 2 (hearing aids). It is not a requirement to participate in the administration, 6-week use, and re-testing procedures involved in Part 2 of the study. All cognitively healthy participants will be invited to participate, only MCI patients with a live-in informant will be given this opportunity. After ear measurement and dome and wire length selection, Oticon Opn S 1 miniRITE hearing aid fitting will occur wirelessly using Genie software, followed by hearing aid use instructions. The fitting will use Open domes, the standard NAL-NL2 protocol, and will increase gain seven steps on top of Real Ear Unaided Gain (REUG) from 750 Hz to 6 kHz.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science