Walk into a busy restaurant in Limassol on a Friday night and within minutes you are leaning forward, raising your voice, straining to follow a conversation. The room is full but not unreasonably so. The music is not particularly loud. Yet somehow every conversation in the room seems to be competing with every other one.

The same thing happens in open plan offices, glass meeting rooms and hotel lobbies. The space looks beautiful. The acoustic experience is exhausting. The culprit in almost every case is reverberation.

What Reverberation Actually Is

When sound is produced in a room it does not simply travel from source to listener and stop. It bounces off every hard surface it encounters, walls, floors, ceilings, glass, concrete and tiles, repeatedly reflecting until it gradually loses energy and fades. Reverberation time, measured as RT60, is the time it takes for sound to decay by 60 dB after the source stops. In practical terms it is a measure of how long sound lingers in a space after it is produced.

In a concert hall designed for orchestral music, a long reverberation time of 1.8 to 2.2 seconds is desirable as it creates a sense of richness and envelopment that enhances the musical experience. In a restaurant or meeting room, the same reverberation time is a serious problem.

What Happens in a Loud Restaurant

A busy restaurant generates a continuous background of noise from conversation, cutlery, kitchen sounds and music. In a reverberant space, every sound produced adds to an accumulated tail of reflected energy that never quite settles before the next sound arrives. The result is a rising noise floor. As the room fills and conversations get louder to compete with the background, the background itself gets louder, people raise their voices further, and the room gets louder still. This self-reinforcing cycle is known as the Lombard effect and it is the reason a half-full restaurant can feel unbearably loud within an hour of opening.

Noise levels in restaurants are consistently cited among the leading causes of a negative dining experience, frequently ranking alongside or above food quality in customer satisfaction surveys. For operators investing heavily in kitchen talent and interior design, the acoustic environment is frequently the weakest link.

What Happens in a Reverberant Office

In a meeting room or open plan office the consequences are different but equally damaging. Reverberation smears speech and each syllable spoken overlaps with the reflected tail of the previous one, reducing the clarity of what is being said. Speech intelligibility, measured through metrics like D50 and STI, falls as reverberation time increases and below a certain threshold listeners have to work significantly harder to follow conversation. Over the course of a working day this cognitive load accumulates into fatigue, reduced concentration and lower productivity.

In video conferencing the problem compounds further as microphones pick up the reverberant tail along with the direct speech signal and transmit both to remote participants, who receive a degraded signal they cannot compensate for by leaning in or asking for repetition.

Why Modern Interiors Make It Worse

The surfaces that dominate contemporary interior design are almost universally poor acoustic absorbers. Exposed concrete, polished stone, ceramic tiles, glass partitions, timber flooring and plaster ceilings all reflect the majority of sound energy that strikes them. The trend towards hard minimal interiors in both hospitality and commercial spaces has been accompanied by a steady increase in acoustic complaints. The aesthetic rationale is clear but the acoustic consequences are predictable and well understood.

Soft furnishings, carpets, upholstered seating and fabric wall panels absorb sound energy and reduce reverberation time significantly and as these elements have been designed out of modern interiors in favour of cleaner harder finishes, the acoustic environment has deteriorated accordingly.

What the Target Should Be

For a restaurant used primarily for conversation, reverberation time should sit between 0.6 and 0.8 seconds across the mid frequencies. For a meeting room the target is tighter, typically 0.4 to 0.6 seconds, since speech clarity is the primary requirement and there is no background music or ambient noise to mask minor acoustic deficiencies.

Most untreated hard surface interiors return reverberation times well above these targets and values of 1.5 to 2.5 seconds are common in spaces with no acoustic treatment, which means the environment is working against its intended purpose from the moment it opens.

What Can Be Done

Reducing reverberation time requires increasing the total absorption in the space through a combination of acoustic ceiling treatment, wall panels, soft furnishings and floor finishes, with the specific approach depending on the room geometry, the surface areas available and the target reverberation time.

The critical point is that acoustic treatment works best when it is designed into a space from the outset rather than retrofitted after complaints begin. The same amount of absorptive material distributed thoughtfully across a ceiling and walls during fit-out delivers far better results than panels added to a finished interior where placement options are already constrained. An acoustic study at the design stage quantifies the problem before the space is built, specifies the treatment required to meet the target, and removes the guesswork from a decision that significantly affects how the finished space will be experienced by everyone who uses it.

If you are designing or fitting out a restaurant, bar, office or hospitality space and want to get the acoustic environment right from the start, get in touch.

Ελληνική Περίληψη

Η αντήχηση είναι ο κύριος λόγος που εστιατόρια και γραφεία ακούγονται δυνατά και κουραστικά, ακόμα και όταν δεν υπάρχει υπερβολικός θόρυβος. Σε χώρους με σκληρές επιφάνειες όπως γυαλί, σκυρόδεμα και πλακάκια, ο ήχος αντανακλάται επανειλημμένα δημιουργώντας ένα συσσωρευμένο ηχητικό υπόβαθρο που κάνει τη συνομιλία κουραστική. Ο στόχος για εστιατόρια είναι χρόνος αντήχησης 0.6 με 0.8 δευτερόλεπτα και για αίθουσες συσκέψεων 0.4 με 0.6 δευτερόλεπτα. Χωρίς ακουστική μελέτη στη φάση σχεδιασμού, οι περισσότεροι χώροι ξεπερνούν αυτούς τους στόχους σημαντικά.

📧 info@nodeacoustics.com