CMD 276 Lecture Notes - Lecture 2: Root Mean Square, Amplitude, Squared Deviations From The Mean

• School: URI
• Department: Communicative Disorders
• Course: CMD 276
• Professor: Milner Bethany

Document Summary

Amount of vibratory displacement during any given point along the waveform. Point of positive or negative maximum displacement. Total distance from point of maximum positive displacement to maximum negative displacement. Must use absolute value on negative value. Otherwise, values would cancel out rms amplitude: Square root of the mean of the squared deviations of the instantaneous pressure. Must square all the values to make them positive. Find the square root of that number. For a sine wave rms amplitude = peak amplitude x 0. 707. Point in a cycle when an object begins to vibrate. Instantaneous phase - measurement of phase at any point along the waveform. Distance between 2 consecutive position peaks (condensation/compression) or 2 consecutive negative peaks (rarefaction) in a wave. Directly affected by frequency and speed of sound. Speed of sound in air is constant. C = 344 m/sec = 1100 ft/sec. Sound will travel at different constants in liquids and solids.