What is Reverberation Time?

Why does sound linger in some rooms more than others? Reverberation Time — commonly referred to as RT60 — is the time it takes for sound to decay by 60 decibels after a sound source stops. It’s one of the most important measurements in room acoustics, shaping how we hear speech, music, and ambient sound in different spaces. There are also shorter versions of this metric: RT20 and RT30, which measure decay over 20 dB and 30 dB ranges, respectively. These are often used in practical measurements where achieving a full 60 dB decay isn’t feasible, helping to provide accurate estimates of RT60. Whether you’re designing a lecture hall, assessing classroom acoustics, or tuning a recording studio, reverberation time is crucial for clarity, comfort, and compliance. In this video, we break down RT60, RT20, and RT30 — what they mean, how they're measured, and why they matter. Want more practical insight into the world of acoustics? Visit the AcSoft Knowledge Hub — packed with FAQs, guides, and expert advice on everything sound-related. 👉 https://acsoft.co.uk/support/