Before sound systems existed, the large grand Cinemas of the past were modelled on Opera houses with an orchestra pit in front of the screen which was later replaced by an organ that came up through the floor.   Opera houses evolved to make use of reverberation to increase sound level to the audience.   Many composers including Mozart hated the excessive reverberation of large concert halls which restricted their music.   Mozart often preferred to perform outside where the detail of the music could be heard as he intended.

The cost of increasing sound level by reverberation is at the loss of intelligibility. What evolved was an imagined ideal of correct reverberation, that is, reflective area around the opera stage of short distances (short path-lengths) opening up to larger areas of longer distances (long path-lengths).

It can be argued that specific pieces of classical music suit different characteristics of reverberation. But there is no such thing as one type of reverberation that suits all classical music and all acoustic instruments. When sound systems evolved, cinemas became trapped with the problems associated with the excessive reverberation of large auditoriums.

The subject of architecture is obsessed with status and visual form, often with little or no interest in what cannot be seen (acoustics). Many architects believe that city environment including our homes and especially auditoriums and cinemas should be as reverberant as possible. Sound absorbed is negatively described as 'room loss'.  Inadequate and false understanding of acoustics has directly contributed to the excessive noise pollution of our cities.

Many early large cinemas had little or no acoustical absorption. Decorative ceilings may provide sound diffusion but little absorption.   No cinema goer is interested at looking at an ornate foyer or the inside of the cinema when watching a film. The money wasted would have been better spent on properly acoustically treating the cinema.

Modern multiplexes often have red pleated curtains on walls, which is mostly decorative and will absorb high frequencies, but may have little effect on absorbing low-frequencies.   Often there is no acoustical absorption on ceilings except for standard acoustical tiles used in most office buildings.

We are also an excellent educator, stated that the 3 Rs of acoustics are –

n   Room resonance

n   Early reflections

n   Reverberation