MUSC 2100 Lecture 4: Sound and Listening
Document Summary
We tend to listen for recognizable patterns that help us distinguish between sounds which are meaningful to us ( signal") and sounds which aren"t meaningful to us ( noise") This ability is often referred to as the cocktail party effect". Reduced listening ("they have a very nasally voice") A sound is a vibrational disturbance in which acoustic energy is transmitted from one place to another by the mechanical motion of air molecules. Frequency spectrum (perceived as tone quality or timbre) Envelope (changes in loudness - also changes in tone quality over time) Imagine that a physical object such as a guitar string is set into vibration. As the string vibrates back and forth at a high rate, the surrounding air molecules are alternately pressed together (compression) then pulled apart (rarefaction) in sympathy with (at the same rate as) the vibrating string. This creates pressure waves which radiate outwards from the string.
