Internet of Sound (IoS): Principles, Technologies, Challenges, and Future Directions

ABSTRACT The Internet of Sound (IoS) introduces a novel communication paradigm that leverages acoustic waves, audible and ultrasonic, as a medium for data transmission. As traditional radio frequency (RF)–based communication faces limitations such as spectrum congestion, energy inefficiency, and interference in sensitive environments, IoS emerges as a complementary solution, offering infrastructure‐free, low‐power, and short‐range connectivity using ubiquitous devices like speakers and microphones. This review systematically explores the foundational principles of IoS, including the physical characteristics of sound propagation and the signal processing techniques required for reliable communication. Key modulation schemes are discussed alongside strategies to mitigate challenges such as ambient noise, multipath interference, and attenuation. The study also examines enabling hardware/software technologies, including real‐time signal processing, synchronization mechanisms, and acoustic stack architectures, emphasizing the balance between complexity and scalability. A comparative analysis with RF‐based systems highlights the contexts where IoS offers distinct advantages, such as enhanced spatial resolution, security in confined environments, and usability in RF‐restricted or underwater domains, while acknowledging RF's superiority in range and throughput. IoS is positioned as a supplementary layer within hybrid communication networks rather than a replacement for RF. The paper identifies major challenges to widespread IoS adoption, including device heterogeneity, environmental sensitivity, and security vulnerabilities. It also underscores the transformative role of artificial intelligence (AI) in enhancing robustness, adaptive modulation, and semantic acoustic understanding. With applications spanning smart infrastructure, healthcare, and human–machine interaction, this study presents IoS as a promising, multidisciplinary frontier for future research and development.