Notes

"to and fro" motion is called oscillation
one oscillation is the movement of the object from one extreme position to another and then back to mean position
Bird - Syrinx
Dolphins - Blowhole
Fish - Air Bladder
Frogs - Air sac
the maximum displacement from mean position on either side is called amplitude
the chain reaction of displacement of molecules from vibrations in the air is called sound wave
sound travels fastest in solids and slowest in air
sound of voice makes metal disc vibrate, the vibration changed into electrical waves which travel through the telephone wires, when these wires reach the other telephone on them and make the disc vibrate.
pinna - outer visible part
eardrum - separates outer ear from middle ear
middle ear - consists of 3 small bones which transmit the vibration of sound to inner ear
inner ear / cochlea - receive sound vibrations and send it to the brain as a signal via auditory nerve
Infrasonic Sounds - 20Hz > - elephants, whales
Ultrasonic Sounds - > 20,000Hz - bats, dogs
sonar - sound navigation and ranging - used for finding depth of ocean / position of submarine
more amplitude --> more loudness
shrillness of sound --> pitch
high frequency --> high pitch
Factors Affecting Pitch:
- Length : Longer the string --> lower pitch
- Thickness : Thicker Strings --> Lower Pitch
- Volume of Air : More volume of air --> lower note
Quality / Timber : Used to distinguish sounds
Stringed Instruments : Violin, Guitar, Sitar, Veena, harp, zither
Wind Instruments : Trumpet, Flute, shehnai, nadaswaram
Percussion Instruments : Drumb, Cymbals, Jal tarang, nout, ghatam, majira