SOUND It is composed of waves of compression and rarefaction in which the human ear is sensitive It is composed of waves of compression and rarefaction in which the human ear is sensitive

-It simply follow an orderly pattern or coherence, of motion. -It can begin either from simple harmonic motions (SHMs) or from complicated motions.

-sound waves carry energy. -sound wave is a longitudinal wave. -the size of a compression indicates how much energy the sound wave has.

Sound is produced when a vibration causes pressure variations in the medium. causes pressure variations in the medium.

sound wave vibrates ear drum amplified by bones converted to nerve impulses in cochlea

Human voice uses several types of sound production and modification of mechanisms.

The vocal chords located in the LARYNX (voice box) in the throat primarily produces the sound for singing and for spoken vowels.

-sounds produced differ because of the differences in SHAPE of the air cavities in the throat, mouth and nasal region.

Propagation of sound Medium - Material that sound waves can travel through. - It can travel through solids, liquids and gases but not through a vacuum.

Sounds possess the characteristics and properties that are common to all waves.

Just like all longitudinal Just like all longitudinal (compression)waves, sound (compression)waves, sound Waves possess a velocity, Waves possess a velocity, frequency, wavelength, frequency, wavelength, phase, period, and amplitude. phase, period, and amplitude. Sound waves also reflect, refract, diffract, and interfere. refract, diffract, and interfere.

Properties of sound waves

II. Properties of Sound

1. PITCH -highness or lowness of a sound. a. FREQUENCY -number of sound waves that passes through a point in a certain amount of time, such as one second. -the greater the frequency, the higher the pitch. Hertz (Hz)- unit to measure frequency and pitch

Audio frequency range -Frequency ranging 20 Hz to Hz -Sounds that human ear can hear is an example. INFRASONICS -Frequency below 20 Hz.

2. LOUDNESS or intensity -description of how high or low the sound seems to a person -determined mainly by the amplitude of the sound wave a. Decibel (dB)- unit used to measure sound intensity or loudness.

SoundLoudness (dbs)Hearing Damage Average Home Loud Music After long exposure Rock Concert Progressive Jet Engine Pain

Threshold of hearing -sound of the quietest sound that can be heard under ideal conditions is 0 dB. Threshold of Pain - Sound level of 120 dB which can pain and damage to the ears. Threshold of hearing -sound of the quietest sound that can be heard under ideal conditions is 0 dB. Threshold of Pain - Sound level of 120 dB which can pain and damage to the ears.

The human ear relates amplitude to loudnessand frequency to pitch.

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 sound 2 Different waveforms 1.Pure tone- simplest wave form, it has a soft, pleasant tone quality and sinusoidal 2.Complex tone- nearly sinusoidal

A. Speed of Sound Depends on: 1. Type of medium -travels better through liquids and solids and gas can’t travel through a vacuum. 2. Temperature of medium -travels faster at higher temperature. 3. Density -sound moves well through dense materials. 4. Elasticity -sound waves move fast through elastic materials

 Doppler Effect  change in wave frequency caused by a moving wave source  moving toward you - pitch sounds higher  moving away from you - pitch sounds lower

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.

Sound waves refract.

B. Reflection of sound Echo- reflected sound - it is what you heard shortly after the original - it is what you heard shortly after the original

C. Diffraction of Sound - Sound waves bend or diffract around corners or barriers like doors and walls.

 the result of two or more sound  waves overlapping

2 types 2 types Constructive interference -the sound waves arrive at the same time and phase Destructive interference -waves arrive at interval and are out of phase

 D. Resonance - the inducing of vibrations of a natural rate by a vibrating source having the same frequency

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. 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.

 Noise- unwanted sound and a subtle pollutant which can threaten the Health or well being of an individual.

CLASSIFICATION OF INSTRUMENTS A.Stringed instruments -Produce a tone when their strings vibrated. B. Wind instruments -contain a column of air that vibrates when air is blown to the instrument C. Percussion instruments -produce sound when they are struck