Non-invasive brain-computer interfaces (BCIs) based on an event-related potential (ERP) component, P300, elicited via the oddball paradigm, have been extensively developed to enable device control and communication. While most P300-based BCIs employ visual stimuli in the oddball paradigm, auditory P300-based BCIs also need to be developed for users with unreliable gaze control or limited visual processing. Specifically, auditory BCIs without additional visual support or multi-channel sound sources can broaden the application areas of BCIs. This study aimed to design optimal stimuli for auditory BCIs among artificial (e.g., beep) and natural (e.g., human voice and animal sounds) sounds in such circumstances. In addition, it aimed to investigate differences between auditory and visual stimulations for online P300-based BCIs. As a result, natural sounds led to both higher online BCI performance and larger differences in ERP amplitudes between the target and non-target compared to artificial sounds. However, no single type of sound offered the best performance for all subjects; rather, each subject indicated different preferences between the human voice and animal sound. In line with previous reports, visual stimuli yielded higher BCI performance (average 77.56%) than auditory counterparts (average 54.67%). In addition, spatiotemporal patterns of the differences in ERP amplitudes between target and non-target were more dynamic with visual stimuli than with auditory stimuli. The results suggest that selecting a natural auditory stimulus optimal for individual users as well as making differences in ERP amplitudes between target and non-target stimuli more dynamic may further improve auditory P300-based BCIs.

基于事件相关电位 （ERP） 组件 P300 的非侵入性脑机接口 （BCI） 已被广泛开发，以实现设备控制和通信。虽然大多数基于 P300 的 BCI 在古怪的范式中使用视觉刺激，但也需要为眼动控制不可靠或视觉处理有限的用户开发基于 P300 的听觉 BCI。具体来说，没有额外视觉支持或多声道声源的听觉 BCI 可以拓宽 BCI 的应用领域。本研究旨在在这种情况下，在人工（例如哔哔声）和自然（例如人声和动物声音）声音中为听觉 BCI 设计最佳刺激。此外，它还旨在研究基于 P300 的在线 BCI 的听觉和视觉刺激之间的差异。因此，与人工声音相比，自然声音导致更高的在线 BCI 性能，并且目标和非目标之间的 ERP 振幅差异更大。然而，没有一种类型的声音能为所有受试者提供最佳性能;相反，每个受试者都表现出人声和动物声音之间的不同偏好。与之前的报告一致，视觉刺激产生的 BCI 表现（平均 77.56%）高于听觉刺激（平均 54.67%）。此外，目标和非目标之间 ERP 振幅差异的时空模式在视觉刺激下比在听觉刺激下更具动态性。结果表明，选择最适合个人用户的自然听觉刺激以及使目标和非目标刺激之间的 ERP 振幅差异更加动态，可能会进一步改善基于 P300 的听觉 BCI。