Seeing a person’s mouth move for [ga] while hearing [ba] often results in the perception of “da.” Such audiovisual integration of speech cues, known as the McGurk effect, is stable within but variable across individuals. When the visual or auditory cues are degraded, due to signal distortion or the perceiver’s sensory impairment, reliance on cues via the impoverished modality decreases. This study tested whether cue-reliance adjustments due to exposure to reduced cue availability are persistent and transfer to subsequent perception of speech with all cues fully available. A McGurk experiment was administered at the beginning and after a month of mandatory face-mask wearing (enforced in Czechia during the 2020 pandemic). Responses to audio-visually incongruent stimuli were analyzed from 292 persons (ages 16–55), representing a cross-sectional sample, and 41 students (ages 19–27), representing a longitudinal sample. The extent to which the participants relied exclusively on visual cues was affected by testing time in interaction with age. After a month of reduced access to lipreading, reliance on visual cues (present at test) somewhat lowered for younger and increased for older persons. This implies that adults adapt their speech perception faculty to an altered environmental availability of multimodal cues, and that younger adults do so more efficiently. This finding demonstrates that besides sensory impairment or signal noise, which reduce cue availability and thus affect audio-visual cue reliance, having experienced a change in environmental conditions can modulate the perceiver’s (otherwise relatively stable) general bias towards different modalities during speech communication.

在听[ba]时看到人的嘴移动[ga]常常会导致“ da”的感觉。这种语音提示的视听整合（称为McGurk效应）在个人内部是稳定的，但在个体之间是可变的。当视觉或听觉线索由于信号失真或感知器的感觉受损而退化时，通过贫困模态对线索的依赖性降低。这项研究测试了由于暴露于降低的提示可用性而导致的提示依赖调整是否持续存在并在所有提示完全可用的情况下转移到随后的语音感知中。在开始强制性口罩配戴（一个月后于2020年大流行的捷克共和国强制实施）后的一个月和之后进行了McGurk实验。分析了292人（16-55岁）对视听不一致的刺激的反应，代表横截面样本，41名学生（19-27岁）代表纵向样本。测试参与者与年龄的互动时间会影响参与者完全依赖视觉提示的程度。在减少了一个月的唇读之后，年轻人对视觉提示（在测试中出现）的依赖程度有所降低，而老年人则有所增加。这意味着成年人可以使他们的言语感知能力适应多模式提示的变化的环境可用性，而年轻的成年人则更有效。这一发现表明，除了感觉障碍或信号噪声外，它们会降低提示的可用性，从而影响视听提示的依赖性，