Delmas Tanguy, Pham Van Cang Mathieu, Gerenton Grégory, Lefeuvre Jérôme, Doelling Keith B, Arnal Luc H, Lazard Diane S
Université Paris Cité, Institut Pasteur, AP-HP, INSERM, CNRS, Fondation Pour l'Audition, Institut de l'Audition, IHU reConnect, F-75012 Paris, France; ECLEAR, Audition Marc Boulet, Audition Lefeuvre, France.
Université Paris Cité, Institut Pasteur, AP-HP, INSERM, CNRS, Fondation Pour l'Audition, Institut de l'Audition, IHU reConnect, F-75012 Paris, France.
Hear Res. 2025 Jul 3;465:109355. doi: 10.1016/j.heares.2025.109355.
In audiological practice, speech comprehension is typically assessed in the auditory modality alone (speech in quiet or noise). However, in real-life communication when the auditory input is degraded - due to noise or hearing loss (HL) - individuals rely on ancillary signals to enhance speech perception. Audio-visual (AV) integration is particularly effective in improving speech perception in noisy environments, yet the influence of HL and aging on this ability remains underexplored. This study aims to disentangle the effects of HL and age on visual aspects of speech processing, both unimodally (lip-reading) and bimodally (AV integration). In sixty-five participants aged 50 and older, with hearing abilities ranging from normal to moderate HL (from 4 to 63 dB HL), we tested speech comprehension in challenging auditory, visual (lip-reading) and AV conditions using an adaptive procedure. AV gain (AV performance minus Auditory-alone performance) served as a measure of audio-visual integration. Using multiple linear regressions and causal inference to account for the relative impact and potential interactions between HL and age, our results show that mild to moderate HL does not improve unimodal visual processing but does improve AV gain. In contrast, aging negatively impacts visual speech processing but does not directly affect AV gain. These findings suggest that mild to moderate HL enhances the integration of visual and auditory speech cues to improve AV performance without affecting the efficacy of the visual information processing itself, while age-related decline in visual speech processing does not appear to effect overall AV integration. We propose that this reflects a form of central plasticity, in which moderate HL drives adaptive changes at high-order multimodal levels, counterbalancing age-related sensory decline in visual speech processing to maintain AV speech integration. Future research should explore how this plasticity evolves with more severe HL.
在听力学实践中，言语理解通常仅在听觉模式下进行评估（安静或嘈杂环境中的言语）。然而，在现实生活中的交流中，当听觉输入因噪音或听力损失（HL）而退化时，个体依靠辅助信号来增强言语感知。视听（AV）整合在改善嘈杂环境中的言语感知方面特别有效，但HL和衰老对这种能力的影响仍未得到充分研究。本研究旨在厘清HL和年龄对言语处理视觉方面的影响，包括单模态（唇读）和双模态（AV整合）。在65名年龄在50岁及以上、听力能力从正常到中度HL（4至63 dB HL）的参与者中，我们使用自适应程序测试了在具有挑战性的听觉、视觉（唇读）和AV条件下的言语理解。AV增益（AV表现减去单听觉表现）作为视听整合的一项指标。使用多元线性回归和因果推断来解释HL和年龄之间的相对影响及潜在相互作用，我们的结果表明，轻度至中度HL不会改善单模态视觉处理，但会改善AV增益。相比之下，衰老对视觉言语处理有负面影响，但不会直接影响AV增益。这些发现表明，轻度至中度HL增强了视觉和听觉言语线索的整合，以改善AV表现，而不影响视觉信息处理本身的功效，而与年龄相关的视觉言语处理衰退似乎不会影响整体AV整合。我们认为，这反映了一种中枢可塑性形式，其中中度HL在高阶多模态水平驱动适应性变化，并抵消视觉言语处理中与年龄相关的感觉衰退，以维持AV言语整合。未来的研究应探索这种可塑性如何随着更严重的HL而演变。
