WP1: PLUS-Auditory Training
The goal of this experimental study is to better understand how task difficulty affects on-task learning thresholds and generalised benefits in two PLUS auditory training tasks involving perceptual and cognitive learning in adults aged 18+ (no upper age limit) with listening difficulties. The main question it aims to answer is:
* Does adjusting task difficulty in PLUS, by manipulating the perceptual and cognitive demands of the phonemic discrimination and competing speech tasks, affect on-task learning thresholds and off-task performance in adults with listening difficulties?
Researchers will compare the two experimental arms (easy/hard) to see whether adjusting task difficulty influences on-task learning thresholds and off-task performance.
Participants will:
* Be randomly assigned to one of two training programs (phonemic discrimination or competing speech) within the two experimental arms (easy/hard); * Perform training for a minimum of 30 minutes per day, 5 days per week, for two weeks (total 10 training sessions, 5 hours of training); * Complete pre- and post- training assessments to measure on-task learning performance and change in performance for untrained measures of speech perception, cognition and self-reported outcomes.
WP2: Post-Training Focus Groups
The goal of this observational study is to gain in-depth qualitative insights into participants' motivations, experiences of task difficulty, and perceived benefits across the PLUS-AT training groups in adults aged 18+ (no upper age limit) with listening difficulties. The main question it aims to answer is:
* How do participants describe their experiences and perceptions of PLUS-AT, particularly regarding task difficulty and self-perceived changes in listening, hearing, thinking, and quality of life?
Researchers will explore participant experiences across the two experimental arms (easy/hard) to determine whether motivations for seeking auditory training, knowledge and beliefs about auditory training, attitudes toward PLUS-AT difficulty, and self-perceived changes in listening, hearing, thinking, and quality of life differ.
A subset of participants (n = 20) will:
* Be invited from WP1 to join one of four online focus groups (60-90 minutes via Microsoft Teams); * Attend the focus group corresponding to their assigned training program (phonemic discrimination or competing-speech) within the two experimental arms (easy/hard); * Share their experiences of completing PLUS-AT.
Adults (aged 18+ years, no upper age limit);
Poorer performance on the DTT (SRT of -5.5 dB SNR or higher, as defined by Dawes, 2013) completed without hearing aid(s) for those who typically use them;
Non-hearing device users or hearing aid(s) owner;
Ability to read and understand English;
Failure to meet inclusion criteria;
Having previous auditory training experience;
Cochlear implant users.
Parallel
Practice Listening and Understand Speech (PLUS)
BehavioralPLUS is a web-based auditory training platform with two adaptive auditory-cognitive training tasks designed to improve listening and communication. Phonemic Discrimination: Phonemes are sounds (e.g. /ba/ vs /da/) that make words different (e.g. "bad" vs "dad"). Participants hear three sounds (e.g., /ba/, /ba/, /da/) from sound pairs (e.g. /ba/ and /da/), and must identify the sound that's different (/da/). Competing Speech: Two talkers produce similar sentences that differ by keywords. Participants are asked to focus on one talker (cued by a target visible on screen) while ignoring a second talker and report two keywords from a list of all possible options.
(Adapted) Coordinate Response Measure (CRM)
This test measures how well participants understand target speech when another talker is present. Two sentences are played at the same time: a female talker (target) and a male talker (distracter). Sentences follow the format 'show the \[animal\] where the \[colour\] \[number\] is', using a fixed target animal (dog) and limited sets of colours and numbers. The distractor never says 'dog' and always names a different animal. Participants identify the colour and number spoken by the female talker while ignoring the male talker, responding via computer or touchscreen. Task difficulty is varied by adjusting the signal to noise ratio (SNR) between target and distracter using an adaptive one up/one down staircase to estimate the speech reception threshold (50% correct). Each run ends after a set number of reversals or trials. Participants complete four runs, with the first as practice. Lower thresholds indicate better performance.
Practice Listening and Understanding Speech (PLUS) Auditory Training
Performance on the trained PLUS tasks (phonemic discrimination and competing speech) will be measured across the 10 training sessions. Each task uses an adaptive procedure to generate a threshold that reflects the level at which participants correctly identify the target speech information 50% of the time. For phonemic discrimination, this is the smallest contrast between speech sounds that can be reliably distinguished. For competing speech, this is the signal-to-noise ratio needed to understand the target talker. Thresholds from each session indicate learning and changes in trained task performance.
Letter N-back
This is a 2-back designed to assess how well participants can keep track of and update information in WM. Letters (A-Z) are presented one at a time, and participants indicate whether the current letter matches the one shown two positions earlier. Each block contains 120 trials: 30 targets (2-back matches) and 90 non-targets. The first two trials are always non-targets. Two distinct versions of the task, each with a different predefined letter sequence, are used to avoid repetition; participants complete one version at pre-training and the alternate version at post-training. Each letter is displayed for 1000 ms within a 2500-ms trial window. Responses are made via keyboard or touchscreen. Accuracy is calculated as correct identification of targets and correct rejection of non-targets, with higher scores indicating better working-memory updating.
Flanker Task
This task measures how well participants respond to a central target while ignoring surrounding distractor items. On each trial, a row of fish appears and participants indicate the direction of the middle fish. One practice block (4 trials) and one test block (12 trials) are completed. Each trial begins with a fixation cross (500 ms in practice; 400, 800, or 1200 ms in test trials). Distractor fish then appear for 1150 ms, with the target fish appearing 200 ms later and remaining visible for 750 ms. Participants respond using 'Q'/'P' keys or touchscreen buttons. Feedback is shown for 500 ms. Trials are easier when distractors point the same way as the target and harder when they point the opposite way. Performance is based on response speed and accuracy, with higher scores indicating better ability to manage distracting information.
Dual-task of Listening and Memory
Participants complete two tasks at the same time: remembering a sequence of five visually presented digits and repeating spoken words in background noise. Each trial begins with a five-digit string shown for five seconds. Participants then hear five monosyllabic words (AB Isophonemic lists) presented in 0 dB ICRA multitalker babble. Words appear one per screen, beginning 250 ms after screen onset, with the noise continuing for 3000 ms. After typing each word, the next screen appears. Once all five words are entered, participants recall the original five digits. There are four trials in total, with trial order randomised. Scores range from 0-20 for correctly repeated words and 0-20 for correctly recalled digits. Two distinct digit-word lists are used: List 1 is completed in Week 1 (pre-training) and List 2 in Week 2 (post-training).
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University of Nottingham
Lead sponsor
National Institute for Health Research, United Kingdom
Collaborator
