Speech Perception and High Cognitive Demand

Change in speech-in-noise perception

In the Quick Speech-in-noise task (QSIN). Participants listen to a target female speaker in babble across six sentences (i.e., one list) presented at different signal-to-noise ratios (SNRs). Each sentence has five target words that participants are asked to repeat at the end of each sentence. Within each list, the first sentence is played with a 25 dB SNR and SNR decreases as the list progresses in increments of 5 dB., with the final sentence played at 0 dB. The average SNR score is calculated across several lists. The average SNR score is calculated across several lists. Scores range from -4.5 to 25.5 dB. Higher scores indicate greater SNR loss (i.e., worse hearing).

Audiobook - Change in pupillary response

During an audiobook listening task, pupil dilations are recorded as an objective measure of listening effort, with larger pupil dilations indicating increased listening effort. Change in pupil dilations at pre and posttest (before and after training, respectively) will be measured. In the audiobook listening task, audiobook segments will be presented to participants at signal-to-noise ratios (SNRs) of quiet, 0 dB, -6 dB, and in babble (with four background speakers). Participants listen to each audiobook segment three times.

Audiobook - Change in magnetoencephalography (MEG) temporal response function

During an audiobook listening task, MEG neural activity will be recorded. The investigators will evaluate change in the temporal response function (TRF). The TRF relates how the brain responds to acoustic stimuli and can be viewed as evoked responses to the continuous speech. Audiobook segments will be presented to participants at signal-to-noise ratios (SNRs) of quiet, 0 dB, -6 dB, and in babble (with four background speakers). Participants listen to each audiobook segment three times.

Change in Magnetoencephalography (MEG) stimulus reconstruction accuracies and integration window analysis

During an audiobook listening task, MEG neural activity will be recorded. The investigators will measure how far the neural response tracks the speech stimulus by stimulus reconstruction accuracies and how the stimulus reconstruction accuracy builds up over time by integration window analysis. Audiobook segments will be presented to participants at signal-to-noise ratios (SNRs) of quiet, 0 dB, -6 dB, and in babble (with four background speakers). Participants listen to each audiobook segment three times.

Audiobook - Change in subjective ratings

During an audiobook listening task, participants provide subjective listening effort and speech intelligibility ratings. This is an experimenter-generated measure. Audiobook segments will be presented to participants at signal-to-noise ratios (SNRs) of quiet, 0 dB, -6 dB, and in babble (with four background speakers). Participants listen to each audiobook segment three times and after each triad of audiobook segments, participants answer subjective intelligibility and listening effort questions. Scores are on a scale from 0 to 10 in increments of 1. Higher subjective intelligibility ratings indicate easier intelligibility whereas higher listening effort indicates more listening effort was exerted while listening to the audiobook segments.

Tone cloud - Change in auditory stream segregation accuracy

As a measure of change in auditory stream segregation, participants complete a stochastic figure-ground (SFG) task, in which participants listen to inharmonious 50 ms tones with random onsets for six seconds. For half of these stimuli, a figure "pops-out" from the background tones, in which a number of tones begin at the same time, making a chord. This figure chord repeats 12 times over the course of three seconds. Participants indicate when they detect a figure chord. The stimuli that contain the figure chord have chords consisting of 4, 6, or 8 tones. Figure detection accuracy will be calculated as percent correct for each figure chord condition.

Tone cloud - Change in auditory stream segregation reaction time (RT)

As a measure of change in auditory stream segregation, participants complete a stochastic figure-ground (SFG) task, in which participants listen to inharmonious 50 ms tones with random onsets for six seconds. For half of these stimuli, a figure "pops-out" from the background tones, in which a number of tones begin at the same time, making a chord. This figure chord repeats 12 times over the course of three seconds. Participants indicate when they detect a figure chord. The stimuli that contain the figure chord have chords consisting of 4, 6, or 8 tones. RT to the figure present stimuli will be calculated as average RT for each figure chord condition.

N-back task - Change in accuracy

Because the auditory and auditory-cognitive training paradigms involve a working memory component, pre and posttests of an n-back working memory measure are included. Participants complete four blocks in which they listen to a string of letters spoken by a female speaker. Participants are asked to click a button when a letter occurred n-back. Each block increases in the nth element that needs to be remember, starting at n = 1 (Block 1) and ending at n = 4 (Block 4). Participants' accuracy as percent correct are averaged for each level of n.