Reverberation Time, RT60 and What It Means for Your Studio

Speech is made of quick consonants and short pauses. When the room keeps sounding after each syllable, those consonants start to overlap with the echo of the one before. Words lose their edges, and listeners at home work harder to follow them without knowing why they are tiring.

This is felt most in news and interview formats, where several people talk in quick exchanges and the talkback in the gallery has to stay clear too. A presenter reading a script on a long reverberant set may sound perfectly pleasant in the studio and still be difficult on air.

Long reverberation also makes the sound change as people turn their heads or lean in. A guest who shifts away from the microphone brings more room into the signal, and the audio mixer ends up chasing levels that a drier room would have kept steady.

Measurement is simple in principle. A loudspeaker plays a controlled burst or sweep, a calibrated microphone records how the room responds, and software works out the decay time at different frequencies. We take readings at more than one position, because a room is rarely the same at the presenter desk as it is near a glass wall.

The set as it will be used matters. We measure with furniture, backdrops and, where possible, a representative number of people present, since a crowd absorbs a surprising amount of sound. A reading taken in an empty, half-built studio can mislead.

Priya writes the findings up in plain terms: what the room does, which frequencies cause trouble, and what changes would help most. Nothing is added to the walls until the client has read the findings and agreed the direction.

A single RT60 number hides detail. Two rooms can share the same average and sound quite different, because one holds its low frequencies for much longer than the other. That is why we look at the figure across the frequency range rather than quoting a single value and moving on.

Background noise belongs in the same discussion. A room that decays well but sits beside a ventilation duct or a busy corridor will still let unwanted sound into the microphones. Reverberation and noise are related problems and are best looked at together, with the heating, lighting fixtures and cabling in view.

The useful question is always what the audience and the gallery actually hear. If dialogue is clear in the control room and on air, the numbers are doing their job. If it is not, the numbers tell us where to look next.

Before buying panels, ask what is wrong in specific terms. Is speech unclear, is there a ring or flutter between parallel walls, does noise leak in from outside? Each symptom points to a different remedy, and a clear description saves money.

Ask too how the space will change. If a set is rebuilt every season, or a studio doubles as a rehearsal room, treatment that can be adjusted or moved may serve better than fixed panelling. Worth knowing early, because it shapes the whole plan.

Finally, ask for the findings in writing, with the measurement positions and conditions stated. That gives you something to compare against after the work, which is the only honest way to tell whether it helped.