Carolan Peter J, Heinrich Antje, Munro Kevin J, Millman Rebecca E
School of Health Sciences, Manchester Centre for Audiology and Deafness, University of Manchester, Manchester, United Kingdom.
Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom.
Front Psychol. 2024 Jan 25;15:1171873. doi: 10.3389/fpsyg.2024.1171873. eCollection 2024.
Listening effort (LE) varies as a function of listening demands, motivation and resource availability, among other things. Motivation is posited to have a greater influence on listening effort under high, compared to low, listening demands.
To test this prediction, we manipulated the listening demands of a speech recognition task using tone vocoders to create moderate and high listening demand conditions. We manipulated motivation using evaluative threat, i.e., informing participants that they must reach a particular "score" for their results to be usable. Resource availability was assessed by means of working memory span and included as a fixed effects predictor. Outcome measures were indices of LE, including reaction times (RTs), self-rated work and self-rated tiredness, in addition to task performance (correct response rates). Given the recent popularity of online studies, we also wanted to examine the effect of experimental context (online vs. laboratory) on the efficacy of manipulations of listening demands and motivation. We carried out two highly similar experiments with two groups of 37 young adults, a laboratory experiment and an online experiment. To make listening demands comparable between the two studies, vocoder settings had to differ. All results were analysed using linear mixed models.
Results showed that under laboratory conditions, listening demands affected all outcomes, with significantly lower correct response rates, slower RTs and greater self-rated work with higher listening demands. In the online study, listening demands only affected RTs. In addition, motivation affected self-rated work. Resource availability was only a significant predictor for RTs in the online study.
These results show that the influence of motivation and listening demands on LE depends on the type of outcome measures used and the experimental context. It may also depend on the exact vocoder settings. A controlled laboratory settings and/or particular vocoder settings may be necessary to observe all expected effects of listening demands and motivation.
听力努力（LE）会因听力需求、动机和资源可用性等因素而有所不同。与低听力需求相比，动机被认为在高听力需求下对听力努力的影响更大。
为了验证这一预测，我们使用音调声码器操纵语音识别任务的听力需求，以创建中等和高听力需求条件。我们使用评估性威胁来操纵动机，即告知参与者他们必须达到特定的“分数”，其结果才可用。通过工作记忆广度评估资源可用性，并将其作为固定效应预测变量纳入。除了任务表现（正确反应率）外，结果指标还包括LE指标，如反应时间（RTs）、自我评定的工作量和自我评定的疲劳程度。鉴于在线研究近来颇受关注，我们还想研究实验环境（在线与实验室）对听力需求和动机操纵效果的影响。我们对两组各37名年轻成年人进行了两项高度相似的实验，一项实验室实验和一项在线实验。为使两项研究中的听力需求具有可比性，声码器设置必须有所不同。所有结果均使用线性混合模型进行分析。
结果表明，在实验室条件下，听力需求影响所有结果，听力需求越高，正确反应率显著降低，反应时间越慢，自我评定的工作量越大。在在线研究中，听力需求仅影响反应时间。此外，动机影响自我评定的工作量。在在线研究中，资源可用性仅是反应时间的显著预测变量。
这些结果表明，动机和听力需求对LE的影响取决于所使用的结果指标类型和实验环境。这也可能取决于确切的声码器设置。可能需要一个受控的实验室环境和/或特定的声码器设置，才能观察到听力需求和动机的所有预期效果。
