- Speech Intelligibility Index ("SII")
The Speech Intelligibility Index (SII) is a quantitative metric that predicts how intelligible speech will be within a specific acoustic environment. It analyses the signal-to-noise ratio (SNR) across multiple frequency bands, assigning weights to each band based on its importance for understanding speech.
The SII ranges from 0 (no intelligibility) to 1 (perfect intelligibility), where higher values indicate clearer and more understandable speech. Unlike simpler measures, the SII accounts for factors such as background noise, reverberation, and bandwidth limitations, making it a versatile tool for assessing communication systems, hearing aids, and acoustic environments.
Widely used in designing and evaluating communication systems, the SII helps ensure speech clarity in environments where effective communication is essential, such as workplaces, public spaces, and emergency scenarios.