What does STI mean in TELECOM

The Speech Transmission Index measures the intelligibility of speech by taking into account signal quality, ambient noise levels, and reverberation time.

The STI is typically measured using a dedicated test signal that is generated based on a known human voice sample. This test signal passes through the audio system under evaluation and is then compared to a reference signal in order to determine its quality and intelligibility. A numerical value assigned between 0-1 represents the result of this comparison with 1 representing perfect intelligibility.

Generally speaking, an STI score of 0.7 or higher indicates good speech intelligibility for most applications. However, it's important to keep in mind that this value may vary depending on the individual's ability to hear as well as other factors such as background noise or reverberation time.

Any audio system where speech transmission needs to be optimized will benefit from an STI measurement, ranging from small conference rooms to large theatres and auditoriums.

Yes, most countries have their own standards and regulations regarding acceptable levels of audible sound quality in public places, particularly places which are designed for audio-visual presentations, such as movie theatres or concert halls. It's important to consult these local standards when performing any kind of STI testing in order to ensure compliance with relevant laws and regulations.