ACOUSTICAL EFFECTS Electronic Music I Is your name and today’s date on your worksheet? Goal for today- To familiarize you with the properties of a number of special acoustical effects.

SOUND WAVES 1.All sound waves are caused by vibrations. The waves emanate from sources such as- vocal cords, instruments, drums, etc.

EARS 2.These sound waves are received by our ears, and sent to the aural receptor area of our brain. This area has learned or been trained to recognize various sounds, voices or words.

EAR WORKINGS Nerve endings going to brain Sound waves enter ear canal

COCHLEA & PITCH Curved lines represent the auditory nerve going from the basilar membrane to the auditory center of the brain.

REFLECTIONS 3. When sound waves hit objects and bounce back or around they become Reflections.

DELAY 4. The time between the original sound and the first Reflection is called the Delay time.

ECHO 5. A very long Delay between the original sound and the first Reflection is called an Echo. Hello !

REVERB(ERATION) 6.When many fast reflections occur in a confined space and are blurred together by our ears, this is called Reverberation, or Reverb for short.

ENVIRONMENT 7.The number of reflections in a room or space is determined by the acoustics of the environment in which the sound was originally produced. 8.Hard sufaces reflect more sound waves to your ears. These are called “Live” or “Bright” areas. 9.Soft surfaces absorb more sound waves and don’t create as many reflections. These are called “Dead” or “Dry” areas.

MEDIA CENTER (LIBRARY) 10. An example of a very acoustically “Dead” or “Dry” area would be the Media Center. (Why?) Non-Parallel walls (curved) Soft surfaces (carpet, ceiling tiles) Low Ceiling Obstructions (books, furniture)

GYMS 11. An example of a very “Live” or “Bright” area would be the Gym. (Why?) Parallel walls Hard surfaces (concrete, solid floor) High ceiling No obstructions

AUDITORIUM 12.The Auditorium has what we call “good acoustics” for music & plays. (Why?) Combination of hard and soft surfaces Non-Parallel walls Some obstructions High ceiling Megaphone shaped sound shell

DOUBLING 13. When a single Delay is slightly detuned from the original it is called Doubling. (Often used to emphasize key moments of a song.)

CHORUSING 14. When many reflections are slightly detuned from the original it is called Chorusing.

FLANGING (“WAH WAH”) 15.Flanging an audio effect produced by mixing two identical signals together, with one signal delayed by a small and gradually changing period. (Wikipedia sample) The only special effect that did not occur first in a natural acoustical environment before being converted to an electronic version. How was it done? On a Reel to Reel tape deck.

More on Acoustics and the Study of Sound in Unit 4. Questions +/or Thoughts on effects or acoustics?