Sound Waves Flashcards
How are sounds made?
Sounds are made when an object vibrates.
What is a wave?
A wave is said to be an oscillation or vibration that transfers energy.
What type of wave is a sound wave?
A longitudinal wave
In a longitudinal wave what is the direction of transfer or energy?
The direction of the wave is parallel to the movement of the source.
Look at the diagram (label A). What is the scientific term for sections of the wave that are close together?
Compressions
Look at the diagram (label B). What is the scientific term for sections of the wave that further apart?
Rarefactions
What is the speed of sound in air?
340 m/s
What is the speed of sound in water?
1500 m/s
In a longtiduinal wave each particle vibrates ______ and _______.
LEFT and RIGHT
What is meant by the term ‘audible range’?
The audible range is the range of frequencies we can hear.
What is the audible range for the human ear?
•The audible range for the human ear is 15Hz to 20,000 Hz.
The loudness of a sound is called the ___________.
Amplitude
What is the loudness (amplitude) of a sound measured in?
Loudness is measured in decibels (dB)
The diagram shows a human ear. Which part of the ear is part one? How does this part help us hear?
The pinna.
It collects sound waves and funnels them into the ear.
The diagram shows a human ear. Which part of the ear is part two?
The ear cannal.
The diagram shows a human ear. Which part of the ear is part 3?
What happens here?
The eardrum.
Sound waves cause the eardrum to vibrate.
The diagram shows a human ear. Which part of the ear is part 5?
What happens here?
This is called the cochlea.
The cochlea turns the vibrations into electrical signals.
The diagram shows a human ear. Which part of the ear is part 4?
What happens here?
These bones are called the ossicles.
The small bones amplify the vibrations.
The diagram shows a human ear. Which part of the ear is part 6?
What happens here?
The auditory nerve.
The auditory nerve takes the electrical signals to the brain.
Sounds louder than _______ decibels are considered potentially dangerous.
80 decibels
What is ultrasound?
Ultrasound consists of high frequency sound waves with a frequency above the limit of human hearing (20,000 Hz)
The diagram shows four sound waves, J, K, L and M.
Which two of the waves have the same amplitude?
Waves J and L have the same amplitude.
Because the waves are the same height from the rest position to the peak.
Which of the waves would sound the loudest?
Wave K would sound the loudest.
Because it has the highest amplitude.
Only one of the waves is an ultrasound wave.
Which one is the ultrasound wave?
Wave L is the ultrasound wave.
Because it has the highest frequency.
Sound travels through air, water and glass at different speeds. Through which of these materials does sound travel the fastest?
Glass
Why does sound travel faster through glass than through air particles.
The particles in glass are closer together so the energy is transfered faster.
If the frequency is increased, the pitch of the sound becomes ____________.
Higher
If its amplitude is increased, the sound becomes _____________.
Louder
What is an echo?
An echo is reflected sound off a surface.
What is reverberation?
Reverberation is when lots of echoes join together to produce a longer sound.
