To reduce reverberation time, sound absorbing materials are the answer. This includes acoustic foam, fabric wrapped acoustic panels, curtains, and anything soft or porous that will not reflect sound waves.
Fabric wrapped acoustic panels typically make the most sense for worship facilities because they look finished, are unobtrusive, and can be installed onto a wall or suspended horizontally or vertically from a ceiling, addressing problem areas.
When acoustic panels are suspended parallel to the ceiling, they are called acoustic ceiling clouds; when they are suspended perpendicular, they are called acoustic ceiling baffles.
These options do not have to impede the traditional design of a worship space. Sticking with a light color scheme, similar or contrasting to the walls and ceilings adds texture and a bit of interest without cluttering the existing layout. However, you are not condemned to this one aesthetic option. Acoustical treatment has become more designer-friendly in recent years.
Acoustic panels are now commonly custom-made in different shapes and sizes, with countless colors and textures of fabric. They can have cutouts, be printed with graphics or photos, and be arranged in any way a designer can dream of. So, while it is usually a first instinct to blend sound absorbing panels into the background when retrofitting, designers have the freedom to create an acoustical treatment that stands out for the right reasons and improves the original design—instead of just preserving it.