Epiphenomenalism: For every physical property P, there is no mental property M that is causally sufficient for P

The room must have a reverberation time of 0. sec-onds for acoustic music, and a reverberation time of 0.3 seconds for electrically amplified music. In other words, the type of music being played in a music room makes a big difference.

Acoustic music needs a response from the room, so it is highly dependent on the room shape. Thus, a long reverberation time creates a better sound – the reason why people enjoy singing in the bathroom is that the reverberation creates a fuller voice. In a very small room, it may be difficult to bring out the lowest notes because of their long wavelength. That

is why a music room needs to be a certain size if very deep instruments will be played in it. In rooms intended for classical music, the absorbers should also have limited absorption and good reflection.

Panel structures can sometimes create resonance or

“sing along”, so to speak – for example instruments like the piano, double bass and cello have a stronger sound if they are in contact with a hollow floor structure. Sound barriers on the ceiling and walls should also be avoided in rooms intended for music and singing without amplification, as they can produce delayed echoes.

With electrically amplified music, the room must affect the sound as little as possible. The room should not play along. The sound must therefore be dampened as much as possible using absorbers on the walls and ceiling. The floor should be fitted with carpets, and if the walls are angled in relation to each other, the sound will be absorbed even more.

If acoustic music and electrically amplified music will be played in the same room, reversible acoustic panels can be installed on the walls. Reversible acoustic panels have an acoustically absorbing material on one side and a reflecting material on the other. The reflecting side is used for acoustic music, and the sound absorbing side is used for electrically amplified music.

In rooms intended for classical music, the absorbers should have limited absorption and good reflection.

Conference rooms must be good for one-way communication from a platform, while also allowing dialogue to take place.

Academy of music, Helsinki, Finland. Photo: Finn Manford

Emirates Aviation College, Dubai. Photo: Birgitte Godsk

In lecture halls, the amount of dialogue between the lecturer and the audience is usually very limited.

This means that the room must be designed for good speech intelligibility from the platform.

Seminar Centre, Holbæk, Denmark. Photo: Martin Tørsleff

CHAP9 DIFFERENT ROOMS, DIFFERENT ACOUSTICS

CINEMAS

In cinemas, it must not be possible to hear the room at all – the only audible sound should come from the speakers. To achieve the optimum sound, the room must have many speakers and the reverbera-tion time must be brought as low as possible. When the reverberation time is greatly reduced, other sounds that were concealed before become more prominent. In some situations, even very quiet sounds can create echoes if the sound source has a flat surface, for example when a door closes. To pre-vent echoes, all surfaces must be angled by at least 6 degrees to each other. If the surfaces in a cinema are parallel and cannot be angled in this way, sound diffusing structures on surfaces are vital.

Other recommendations

• Because the absorbers are installed in the field of peripheral vision, the surfaces should be matt and rough textured to prevent glare and light reflection.

• The materials should also be dark and light-absorbing.

• The wall materials must be child-proof and impact resistant.

HOSPITALS

For many people, a hospital stay is a time of uncer-tainty: they are away from home and do not always know what to expect. There are lots of unfamiliar sounds in a hospital, and this can also be unset-tling. So the individual wards must be well insulated from the sounds outside, creating an atmosphere of intimacy and safety on the ward. Large amounts of hard materials tend to be used in hospitals, which need to be counteracted by similar amounts of absorbers.

It is important for hospital wards to be effectively shielded from external sounds, in order to create an atmosphere of intimacy and safety.

In cinemas, sounds from the audience must be dampened as much as possible.

Biocity, Aalborg, Denmark. Photo: Finn ManfordHolbæk Hospital, Denmark. Photo: Finn Manford

Other recommendations

• The materials must be easy to clean.

• The materials must only accumulate or give off minimal quantities of dust, to avoid dam-aging sensitive instruments and impairing hygiene.

• In some rooms there is overpressure above the ceiling for reasons of hygiene, requiring additional stability in the ceiling structure.

• In operating theatres, porous materials are not recommended because bacteria and other impurities can settle there.

• In a hospital environment, bright, warm colours often give a greater feeling of secu-rity.

RESTAURANTS

It is difficult to formulate clear rules for the acoustic environment in restaurants and other eating

estab-lishments, because not all restaurants are trying to create the same atmosphere. If it is the kind of res-taurant where people meet with friends before a night on the town, the sound environment should be much livelier than in a quiet, romantic restau-rant. Basically, the sound needs to match the res-taurant, so the architect should always find out as much as possible about what the restaurant will be like. Will the customers sit at long refectory tables or in small, cosy alcoves? With refectory tables, noise from the other guests is part of the atmos-phere, but alcoves must feel isolated, giving guests a sense of being in their own little world.

In general, though, it is true to say that acoustics have not been taken into account at all in many new restaurants. Large glass facades and hard materials on floors and walls amplify the noise from the other guests, so you virtually have to shout at each other. That is why it is a good idea, even in lively restaurants, to spread and dampen the sound in selected places.

In a restaurant where people meet with friends before a night on the town, the sound environment should be livelier than in a quiet romantic restaurant.

Hotel Scandic Rubinen, Sweden. Photo: Finn Manford