A minimum STI value is considered intelligible?

A minimum STI value is considered intelligible?

• A. 0.3
• B. 0.5
• C. 0.7
• D. 0.9

Answer: (B)

STI, or Speech Transmission Index, measures how well speech signals survive transmission through a room or system. It ranges from 0 to 1, with higher values meaning clearer, more intelligible speech. In practice, about 0.5 is the threshold at which speech becomes intelligible to listeners in typical environments. Values around 0.5 indicate just enough speech cues are preserved for understanding, while lower values (like 0.3) are generally unintelligible. Higher values (0.7 or 0.9) show much clearer speech, but the minimum for intelligibility is 0.5.

STI, or Speech Transmission Index, measures how well speech signals survive transmission through a room or system. It ranges from 0 to 1, with higher values meaning clearer, more intelligible speech. In practice, about 0.5 is the threshold at which speech becomes intelligible to listeners in typical environments. Values around 0.5 indicate just enough speech cues are preserved for understanding, while lower values (like 0.3) are generally unintelligible. Higher values (0.7 or 0.9) show much clearer speech, but the minimum for intelligibility is 0.5.