How important is sound in an interior environment?
One needs to consider the type of atmosphere they want for their patients or clients to experience from the moment they enter. Sound plays a huge part of the first impression. If the experience needs to be fun and lively, then sound attenuation is not really an issue and one can use just about any material they wish.
If the experience needs to be a more calming effect, then special attention needs to paid in several areas. If one thinks about Opera House or theatre design, the best are never designed as a box or a room that has opposing flat walls. They are designed in steps, both vertically and horizontally and most often curvilinear in nature.
Sound reflects directly off of a flat surface. When you have opposing walls that are flat, especially when the floor and ceiling are the same, then sound reverberates creating an echo effect. In some cases it can be perceived as amplification. If there are a lot of different types of sounds at different decibel levels, it can be quite disturbing which does the opposite of calming—it heightens emotional levels. Children get hyper-active. Adults get annoyed and geriatric people get irritable sometimes to the level of angry.
So, the type of facility and desired effect needs to dictate the level of sound attenuation. Curves help dissipate sound. Angles or tilted walls can help as well. Soft, sound absorbing surfaces help no matter what and can be emphasized should the ability to create curves or angles be unrealistic for what ever reason.