Platform 4 of the central railway station had a vaulted glass and iron ceiling built in 1897. It was magnificent. It was also an acoustic catastrophe. When the automated announcement system said "The 14:32 train to Manchester is delayed by approximately 15 minutes," passengers on the platform heard a majestic, cathedral-like reverberation that communicated urgency, importance, and absolutely zero specific information.

A tourist from Japan asked a local what language the announcement was in. The local, who spoke English natively, had to admit he wasn't entirely sure. The reverberation smeared consonants so completely that the temporal fine structure of speech — the rapid amplitude and frequency changes that distinguish "p" from "b" from "d" — was destroyed. Only the vowel formants survived, creating a haunting, melodic sound with no linguistic content.

The platform's STI measured 0.19. The vaulted ceiling focused reflections into a caustic pattern at ear height, creating constructive interference that was louder than the direct sound from the speakers. Passengers were hearing more reflected energy than direct energy, which is the acoustic definition of unintelligible.

Victorian-era stations were designed for steam and grandeur, not for PA systems that wouldn't be invented for another 50 years.

The Moral: Heritage buildings present extreme acoustic challenges. Measure STI with SonaVyx STI before designing the PA system — you may need directional line arrays and aggressive time alignment to achieve intelligibility in spaces that were never designed for speech.