12. Sound Flashcards
What is the speed of sound directly proportional to?
The medium in which it travels.
Where does sound travel fastest?
In solids (which have the densest molecules), then liquids, then gases.
How fast does sound travel through air?
331 m/s + 0.6 m/s times temperature.
What is sound intensity?
The power of sound divided by the area.
What is sound intensity measured in?
The decibel scale.
What is pitch?
Pitch is the sensation of frequency. The higher the pitch, the higher the frequency.
When an object and source both move towards each other and the frequency appears to shift, what is this called?
The Doppler effect.
In the Doppler effect, what happens when an object and source move away from each other?
The frequency appears to downshift.
What are the 3 parts of the ear that aid hearing?
Outer ear - collects and amplifies sound. Middle ear - transmits vibrations from the eardrum to a smaller drum called the oval window. Inner ear (filled with fluid) - turns vibrations into neural signals that are sent to the brain and processed.
What is the range of human hearing?
20Hz to 20,000Hz.
What is sound below human hearing called?
Infrasound.
What is sound above human hearing called?
Ultrasound.
