Topic 9- The auditory System Flashcards
What are the two definitions of hearing?
8pts
Physical definition:
- Does the sound happen even if someone isn’t present ?
- Sound is pressure changes in the air (or other medium)
- “The sound of the trumpet has a frequency of 1000hz”
Perceptual definition:
- What if no one is present?
- Sound is the experience we have when we hear
- “The sound of the trumpet filled the room”
When does a physical sound stimulus occur?
A physical sound stimulus occurs when the movement or vibrations of an object causes pressure changes in air, water, etc
What happens when a speaker vibrates ?
When a speaker vibrates it affects the surrounding air and produces both increases and decreases in pressure.
What is compression in a speaker?
When the speaker moves out, it pushes air molecules closer together and increases air pressure
What is rarefaction in a speaker?
When the speaker moves back in, air molecules spread back out and decreases air pressure
By repeating compression and rarefaction hundreds of times per second, this process produces a …
A sound wave
What is a pure tone?
A tone that can be described by a single sine wave
What is frequency?
3pts
- Number of cycles per second the pressure change occurs
- Number of “repeats”
- Measured in Hz
What is amplitude?
3pts
- The size of pressure change that occurs
- Difference between the peak and valley of the sine
- Measured in dB
Are pure tones or complex tones rare?
Most environmental sounds are what type of tones?
2pts
- Pure tones are rare
- Most environmental sounds are complex tones ( Made up of several pure tones that are added together)
What are the 3 perceptual dimensions of sound?
3pts
- Loudness (volume/intensity)
- Pitch
- Timbre
The smallest amount of sound energy that can just barely be detected
Threshold or loudness? Give an example.
- Threshold
- “Can you hear it?”
The perceived intensity of a sound that ranges from “very quiet” to “very loud”
Threshold or loudness? Give an example.
2pts
- Loudness
- “How loud does it sound?”
What is loudness? What is it closely related to?
BLANK dB is considered the absolute threshold for human hearing
–> Assuming normal functioning….
Intensities above ~BLANK dB can cause permanent damage to the sensory receptors inside our ears
- The perceptual quality most closely related to the amplitude of an auditory stimulus
- 0
- 120
In the human audibility curve, we hear sounds within a specific range of frequencies, which area signifies the auditory response area
The green area
We are most sensitive to sounds between BLANK and BLANK Hz.
What does this signify ?
2pts
- 2000Hz and 5000Hz
- This is around the frequency of human speech