Topic 9 Flashcards
Why is hearing important from an evolutionary perspective?
Hearing is imperative to detect stimuli that we cannot see.
How do ears enhance our perception?
Ears on the sides of the head widen our scope of perception, allowing us to detect sounds from areas our eyes can’t see.
What is sound?
Sound is the subjective and cognitive interpretation of auditory stimuli, involving the brain’s processing of sound waves into meaningful experiences like pitch, loudness, and timbre.
What happens when a tree falls in a forest with no one to hear it?
Physics-wise, there will still be a sound due to pressure changes in the air, but without a recipient to perceive it, there is no sound.
What is physical sound?
Physical sound is when a stimulus creates movements or vibrations that cause pressure changes carried in a medium, typically air.
What are pure tones?
Pure tones constitute a single sine wave, featuring one positive parabola and one negative parabola.
What are frequencies?
Frequencies are the number of cycles per second, measured in Hz.
What is the human perceptible frequency range?
Humans can perceive frequencies from 25 Hz to 20,000 Hz.
What is amplitude?
Amplitude is the size of the waves, measured in dB, and represents the difference between the peak and valley of the sine wave.
What are complex tones?
Complex tones are imperfect tones that consist of multiple pure tones added together.
What are the three perceptual dimensions of sound?
- Loudness 2. Pitch 3. Timbre
What is loudness?
Loudness is the perceptual quality closely related to the amplitude of the sine wave and is the subjective perception of sound pressure.
What is the human audibility curve?
The human audibility curve is a graph representing the threshold of hearing for an average human across different frequencies.
Why are humans most sensitive to sounds between 2000 Hz and 5000 Hz?
This sensitivity likely provides an evolutionary advantage for enhanced speech perception and communication.
What happens in the ear when sound waves travel through?
The ear takes sound pressure changes and vibrations, which travel through different structures for the brain to register.
What is the outer ear’s function?
The outer ear collects sound waves and protects the inner structures while slightly increasing the amplitude of some sound frequencies.
Why are children’s ears more sensitive than adults’?
Children have shorter ear canals, leading to faster auditory resonance and amplified frequency perception.
What is the tympanic membrane?
The tympanic membrane, or eardrum, is the boundary between the outer ear and middle ear and is crucial for sound transmission.
What does the middle ear contain?
The middle ear contains the three smallest bones in the body: malleus (hammer), incus (anvil), and stapes (stirrup).
Why is the middle ear important?
The middle ear mediates sound transmission from air to fluid in the inner ear, amplifying sound waves.
What is the cochlea responsible for?
The cochlea is responsible for the perception of pitch and is where transduction occurs.
What is the organ of Corti?
The organ of Corti is where hair cells (sensory receptors) are located and is parallel to the eye’s retina.
What is the process of transduction in the cochlea?
Transduction occurs when vibrations from the oval window cause fluid movement in the cochlea, leading to hair cell activation.
What is the tonotopic map?
The tonotopic map describes how different frequencies correspond to specific areas of the cochlea, affecting hair cell bending.
