Audiovisual Entrainment (AVE) is a non-invasive, non-pharmacological neuromodulation approach that aims to align brain activity with externally delivered auditory and visual rhythms. This review surveys AVE's historical development, technical parameters (e.g., frequency, phase, waveform, color, intensity, presentation mode), components and delivery methods, reported clinical applications, and safety considerations. Given the heterogeneity of AVE protocols and terminology, we conducted a structured narrative review (PubMed, Scopus, Google Scholar; earliest records to July 2025), including human and animal studies that met an operational definition of regulated AVE and consistent administration of specified auditory and visual frequencies, with critical methodological details reported. We highlight AVE's accessibility and versatility, outline a stepwise parameter reporting framework to support standardization, and discuss putative mechanisms via sensory and oscillatory pathways. However, current findings are heterogeneous and include null or limited effects. Mechanistic understanding and parameter optimization remain insufficiently developed, and premature claims of efficacy are not warranted. Rigorous, standardized, and adequately controlled studies are needed before AVE can be considered a reliable therapeutic tool.
Keywords: audio-visual entrainment; entrainment; neuromodulation.