Speech Intelligibility

Speech intelligibility is a quantitative measure of how well listeners understand spoken content in acoustic environments. Formalized by Steeneken and Houtgast in 1980 with the Speech Transmission Index (STI), intelligibility metrics combine room acoustic parameters (RT60, noise, clarity) to predict listener comprehension. Understanding speech intelligibility is essential for designing classrooms, offices, hearing aids, and public address systems where clear communication is critical.