**Abstract**

Should we consider the acoustics as engineering science or as architectural elements or as interior design applications? The main purpose of this chapter will focus on the differences between the three aspects of the acoustics with a special focus on the interior acoustical design. The arguments that favor the acoustic in each field are many. This chapter will clarify, strengthen, and explore the importance that has the acoustic study for the interior designing layout. From the historical eras where only material schemes were used, the acoustical treatment reached a great achievement. Nowadays, electrical, acoustical devices took place in different situations where only the materials could solve the acoustic needs. The considerations of using the electrical-acoustical devices remain under request, while their usage, only in specific conditions, a topic to highlight in this chapter.

**Keywords:** acoustics for interiors, soundscape, environmental acoustics
