Sensory + Perception Flashcards
Sound Waves
- Vibrations in the air that we can hear.
- Frequency : Number of cycles per second in a wave.
- Determines pitch (high or low sound).
Measured in Hertz (Hz); we hear best at 2000-5000 Hz.
Amplitude
- Height of a sound wave.
- Higher amplitude means louder sound
How the ear hears
- Sound waves enter through the outer ear
- The sound hits the eardrum, making it vibrate.
- The eardrum’s vibrations move three tiny bones (malleus, incus, stapes) in the middle ear.
4.The last bone (stapes) pushes on a small opening called the oval window.
5.This creates waves in the fluid inside the cochlea (a spiral part of the ear).
6.The fluid waves make tiny hair cells in the cochlea bend. - Bending hair cells turn the movement into electrical signals that travel to the brain.
8.The brain receives these signals and helps us recognize the sound.
Tonotopic Map
- Sound travels to the brainstem, then the thalamus, and finally the auditory cortex
Frequency Theory
- Different sound frequencies cause different rates of nerve signals.
- Higher frequencies result in faster nerve firing
Place Theory
- Different frequencies activate specific regions of the basilar membrane.
- The brain identifies pitch based on where activity occurs.
Absolute Pitch
- Ability to recognize or produce any musical note
- More common in speakers of tonal languages (e.g., Mandarin Chinese
Sound Adaptation : Mechanisms
- Muscles around the ears contract to limit sound intake.
- Ears become less sensitive to constant noises.
- The brain filters out unimportant sounds
Cocktail Party Effect
- ability to hear relevant sounds in noisy environments.
Sound Localization : General Loudness
Louder sounds seem closer; we perceive distance based on loudness.
Sound Localization : Loudness in Each Ear
The ear closer to the sound hears it louder due to sound intensity differences.
Sound Localization : Timing
Sound waves reach the nearest ear first, helping the brain locate the sound’s direction.
Prenatal Hearing
Babies can hear sounds before they are born, including voices and music.
Postnatal Development
Infants quickly learn to recognize and respond to familiar sounds, especially their mother’s voice.
Preference for Speech
Newborns show a preference for speech over nonspeech sounds, indicating early social engagement.
Deafness
Can be partial or complete; causes include genetics, infections, loud noises, and trauma.
Tinnitus
A ringing or buzzing sound in the ears; affects about 1 in 200 people; often linked to hearing loss or damage.
Cochlear Implants
Medical devices that can restore some hearing by directly stimulating auditory nerves.
Rods
These help you see in dim light and detect movement. There are over 100 million rods in each eye.
Cones
These help you see colors and sharp images. There are about 4.5 to 6 million cones, mostly in the center of the retina (called the fovea).
Hue
This is the actual color you see, like red, green, or blue.
Saturation
This tells how bright or vivid the color is; more saturation means a brighter color.
Brightness
This is how much light reflects off an object; brighter colors reflect more light.