1. SOUND It is composed of waves of compression and rarefaction inwhich the human ear is sensitive

2. -It simply follow an orderly pattern or coherence, of motion.-It can begin either from simple harmonic motions (SHMs) or fromcomplicated motions. 3. -sound waves carry energy. -sound wave is a longitudinal wave.-the size of a compression indicates how much energy the sound wave has. 4. Sound is produced when a vibrationcauses pressure variations in the medium. 5. B. HUMAN HEARINGsound wavevibrates ear drumamplified bybonesconverted tonerve impulses incochlea 6. Human voice usesseveral types ofsound production and modification ofmechanisms. 7. The vocal chords locatedin the LARYNX (voicebox) in the throat primarily produces thesound for singing and forspoken vowels. 8. -sounds produced differ because of thedifferences in SHAPE of the air cavities in thethroat, mouth and nasal region. 9. Propagation of sound Medium -Material that sound waves can travel through. -It can travel through solids, liquids and gases but not through a vacuum. 10. Sounds possess thecharacteristicsand properties thatare common to all waves. 11. Just like all longitudinal (compression)waves, soundWaves possess a velocity, frequency, wavelength,phase, period, and amplitude.Sound waves also reflect,refract, diffract, and interfere. 12. Properties of sound waves 13. II. Properties of Sound 14. 1. PITCH-highness or lowness of asound.a. FREQUENCY-number of sound wavesthat passes through a pointin a certain amount of time,such as one second.-the greater the frequency,the higher the pitch.Hertz (Hz)- unit to measurefrequency and pitch 15. Audio frequency range-Frequency ranging 20 Hz to 20 000 Hz-Sounds that human ear can hear is anexample.INFRASONICS-Frequency below 20 Hz. 16. 2. LOUDNESS or intensity-description of how high or low the sound seems to a person-determined mainly by the amplitude of the sound wavea. Decibel (dB)- unit used tomeasure sound intensity orloudness. 17. LOUDNESS OF SOUND IN DECIBELSSoundLoudness (dbs) HearingDamageAverage Home 40-50Loud Music 90-100After long exposureRock Concert 115-120 ProgressiveJet Engine 120-170 Pain 18. Threshold ofhearing-sound of thequietest soundthat can beheard underideal conditionsis 0 dB.Threshold ofPain- Sound level of120 dB whichcan pain anddamage to theears. 19. The human ear relatesamplitude toloudness andfrequency topitch. 20. 3. TIMBRE-tone color or tone quality-used to distinguished between two different sounds that have the same pitch and loudness- It helps to identify what produced the sound2 Different waveforms1. Pure tone- simplest waveform, it has a soft,pleasant tone qualityand sinusoidal2. Complex tone- nearlysinusoidal 21. A. Speed of SoundDepends on:1. Type of medium-travels better through liquids andsolids and gascant travel through a vacuum.2. Temperature of medium-travels faster at highertemperature.3. Density -sound moves well through densematerials.4. Elasticity -sound waves move fast throughelastic materials 22. B. DOPPLER EFFECT Doppler Effect change in wave frequencycaused by a moving wavesourcemoving toward you - pitch sounds highermoving away from you - pitch sounds lower 23. A. Refraction of sound-change in direction, as the wave moves from one medium to another- It bends or refracts as they move through air. 24. Sound waves refract. 25. B. Reflection of soundEcho- reflected sound- it is what you heard shortly after the original 26. C. Diffraction of Sound- Sound waves bend or diffract around corners or barriers like doors and walls. 27. D. INTERFERENCEthe result of two or more sound waves overlapping 28. 2 typesConstructive interference-the sound waves arrive atthe same time and phaseDestructive interference-waves arrive at intervaland are out of phase 29. * Fact * D. Resonance- the inducingof vibrations of a naturalrate by a vibrating sourcehaving the same frequency 30. A. Characteristics of musical sounds Note- basic element of music 1. Pitch- highness or lowness of the note 2. Intensity- loudness of the note 3. Rhythm- repeating pattern of beats and it keeps the time to the music 4. Melody- series of pitches 5. Harmony- three or more notes played together. 31. * Fact *Noise- unwanted soundand a subtle pollutantwhich can threaten theHealth or well being ofan individual. 32. CLASSIFICATION OF INSTRUMENTS A. Stringed instruments - Produce a tone when their stringsvibrated. B. Wind instruments -contain a column of air that vibrates whenair is blown to the instrument C. Percussion instruments -produce sound when they are struck