Ch 1-3 Flashcards
Basic anatomy of the Ear
Outer, Middle, and Inner ear. Auditory Cortex
Outer Ear
Collects sound from the environment
Consists of the Helix, Antihelix, External Auditory Meatus, Concha, Tragus, and Lobule
Middle Ear
Modifies/Amplifies sound
Consists of the Eardrum, Malleus, Incus, Stapes, and the Eustachean Tube
Malleus, Incus, Stapes
Bones that act as a lever system and transfer mechanical energy to the chochlea
Eustachean Tube
Equalizes pressure and drains fluid from middle ear into throat
Inner Ear
Consists of the Cochlea and Semicircular Canals
Air Conduction Pathway
Vibrations from the environment through ear canal > ear drum > hearing nerve > auditory cortex
Bone Conduction Pathway
Vibrations from the environment > bones of the skull > hearing nerve > auditory cortex
Conductive Hearing Loss
Issue is with getting sound from the environment to the outer or middle ear. Problem is with air conduction
Attenuation
Decrease in the strength of a sound
Sensorineural Hearing Loss
Damage is in the inner ear. Problem is with bone conduction
Mixed Hearing Loss
Damage to both the outer/middle and inner ear
Erroneous Hearing Loss
Involves a conscious or unconscious faking of hearing loss.
Psychogenic Hearing Loss
Occurs when a psychological disorder manifests as a hearing loss
Sound
Can be defined in either psychological or physical phenomena
Psychological Sound
Sound is auditory experience: act of hearing something
Physical Sound
Sound is a series of disturbances of molecules within and through an elastic medium
Waves
Molecules in the air are disturbed by a body that is set into vibration. They move from the point of disturbance
Made up of compressions and rarefactions
Longitudinal Waves
Air molecules move along the same axis as the wave itself
Sine Waves
One cycle of vibration or oscillation begins at any point on the wave and ends at the identical point on the next wave
Pure Tone
When a body oscillates sinusoidally showing only one frequency of vibration
A steady sound without over tones
Frequency
Measured in hertz (Hz) in cycles per second
Complex Sounds
Sounds that contain a number of different frequencies, amplitudes, and phase relationships
Intensity
How far something vibrates. Amount of wave force per unit of area
Measured in decibels (dB)
Sound Pressure Level (SPL)
Sound pressure measurement.
0dB SPL is not an absence of sound, but it means that the output pressure is 0dB above the reference pressure
Hearing Level (HL)
Audiometers use a dB reference of hearing level
The lowest sound level intensity that stimulates normal hearing is called 0dBHL
Sensation Level (SL)
Auditory threshold of a given individual.
The threshold of a pure tone is defined as the level at which the sound is so soft that it can be perceived 50% of the time
Psychoacoustics
The study of the relationship between physical stimuli and the psychological responses to which they give rise
Pitch
Describes the subjective highness or lowness of a sound.
Its physical relation is frequency
Loudness
a subjective experience of the physical force of intensity
Localization
ability to determine where a sound is coming from. Results from an interaction between both ears. The time at which sound arrives at each ear allows for localization. Requires similar hearing sensitivity in both ears
Pure Tone Audiometer
Comparison of a person’s hearing to an established threshold
Produces pure tones of different frequencies
Air Conduction Testing
tested via headphones or inserts, or can be used in a sound field
Bone Conduction testing
Tested using a small plastic device on a headband placed on the forehead or mastoid bone
Speech Audiometer
required for measurements of speech stimuli. Live or recorded can be used
