What effect does a high Reverberation Time (RT) have on room acoustics?

• A. It can cause echoes and make it difficult to hear speech
• B. It eliminates background noise
• C. It degrades speech intelligibility due to echoes
• D. It reduces overall loudness

Answer: (C)

Reverberation Time is a measure of how long sound energy persists in a room after the source stops. When RT is high, sound reflections linger and overlap with the ongoing speech. This creates a continuous reverberant field that blurs the timing and detail of the spoken sounds, making it harder to distinguish consonants and syllables. The brain struggles to separate the speech from its own reverberant tail, so overall speech intelligibility drops.

Note that this isn’t just about distinct echoes; it’s the persistent energy from many reflections building up and decaying slowly. High RT doesn’t remove background noise or make things quieter; it mainly harms clarity of speech by smearing and masking the spoken message. In spaces intended for clear communication, keeping RT low helps maintain intelligibility.