Speech intelligibility and public sound systems

There’s an important difference between music and speech. The brain is capable of “filling in” a fair amount of missing information in music.  There’s a high degree of predictability. Generally while hearing music, if you didn’t get the bass line or some part of the song which you are keen on listening in the first four measures, you’ll pick it up when it repeats in the next four beats. Speech on the other hand is rich and constantly changing information.

At large distances between a talker and listener, intelligible communication is difficult. If in an enclosed reverberant space, the reverberant sound would mask the speech syllables since the direct sound would be weak and the reverberant sound dominant. As the talker and listener move closer together, the direct sound increases and speech communication improves. Even if a modest percentage of the information is jumbled or missing, the brain can’t decipher the message.

This experiment was conducted to obtain a practical knowledge of speech intelligibility and also gain experience of setting up a public addressed sound system.

For detailed information on the study, performed by Rolins T Roy, Mumbai, India, click below.


Acoustics miscellaneous 285

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