Acoustics may be defined as the scientific study of sound. More explicitly, acoustics deals with vibrational energy: how it is generated, transmitted and received. This encompasses a broad range of fields, such as speech and hearing but also underwater acoustics, structural acoustics, biomedical ultrasound, and much more. (See Lindsay’s Wheel of Acoustics.) In this site, we focus specifically on concert hall acoustics. Click here to review a brief history of architectural acoustics.
How is the sound you hear in a concert hall related to vibrational energy? “Sound” results from pressure fluctuations which travel through the medium of air. Various sound sources generate the air vibrations (such as an opera singer, a violin, a trumpet). The vibrations occur at different rates, resulting in different frequencies of sound, which are perceived by us as different pitches. Low pitched sounds (like that produced from a bass drum) vibrate at low frequencies, such as 20 to 250 cycles per second, or hertz (Hz). High pitched sounds (like that produced from a piccolo) vibrate at high frequencies, such as 5,000 to 20,000 Hz. Humans in general can hear sounds between 20 to 20,000 Hz.
These vibrations emanate in sound waves, which travel around the room, becoming reflected, absorbed or transmitted at the walls or boundaries of the room. For a good concert hall, it is important then to consider the shape and size of the room as well as its material properties.
Click below to learn how each of the following factors affect room acoustics: