AUDIOLOGY- INTRODUCTION (AB) Flashcards
What is audiology?
Audiology is the science of evaluating hearing, diagnosing its causes, assessing its impact, and rehabilitating individuals with communication problems.
What are the key aspects of hearing evaluation in audiology?
Etiological diagnosis, assessment of hearing impairment impact, and rehabilitation guided by hearing measurements.
What is the simplest form of sound?
A pure tone (a single frequency).
How is frequency measured?
In hertz (Hz), which represents cycles per second.
What is sound intensity measured in?
Decibels (dB).
What are the two separate measurements decibels refer to?
Sound pressure level (actual strength of sound) and hearing threshold levels (relation to audiometric zero).
What are the advantages of listening with two ears?
Better speech discrimination in noise, binaural summation (perceived loudness increase), squelch effect (background noise suppression), elimination of head shadow effect, localization, and judgment of naturalness.
What is binaural summation?
The increase in perceived loudness when listening with both ears compared to one ear.
What is the squelch effect?
The suppression of background noise when attending to a primary signal.
What is the head shadow effect?
The phenomenon where sound reaches the nearer ear first, with the head blocking some of the sound before it reaches the other ear.
How does listening with both ears eliminate the head shadow effect?
By allowing the brain to process sound from both sides, compensating for any sound obstruction.
What is sound localization?
The ability to determine where a sound is coming from.
What is judgment of naturalness in hearing?
The ability to differentiate between natural voices and artificial sound systems.
At what sound pressure level (SPL) can noise cause pain?
Noises over 140 dB SPL.
At what SPL can long-term exposure harm hearing?
Noises over 90 dB SPL.
What are the two routes of hearing?
Air conduction (AC) and bone conduction (BC).
What does air conduction (AC) test?
The integrity of the external, middle, and inner ear.
What does bone conduction (BC) test?
The integrity of the cochlea (inner ear) by bypassing the external and middle ear.
What is the process of hearing?
- Sound vibrations strike the eardrum. 2. Auditory ossicles vibrate, moving the stapes at the oval window. 3. Fluid inside the cochlea moves. 4. This movement generates nerve impulses, sent to the brain via the cochlear nerve.
What are the types of hearing loss?
Conductive, sensorineural, and mixed hearing loss.
What is conductive hearing loss?
Hearing loss due to damage in the external auditory canal (EAC) or middle ear (ME) while bone conduction remains normal.
What is sensorineural hearing loss?
Hearing loss due to damage in the cochlea or retrocochlear pathways, where both air and bone conduction are impaired.
What is mixed hearing loss?
A combination of both conductive and sensorineural hearing loss.
What happens when sound collides with the tympanic membrane?
Most of the energy is reflected, causing energy loss.
What is the role of the tympanic membrane in sound perception?
It acts as a critical structure for transmitting sound vibrations to the inner ear.
How does the ear compensate for energy loss when sound enters?
Through impedance matching: the tympanic membrane-to-stapes surface area ratio (17:1) and the ossicular lever system (1.3x), resulting in an efficiency of 22.1.
What is the function of the ossicles in hearing?
They act as a lever system to amplify sound transmission to the inner ear.
What is the function of the basilar membrane?
It vibrates at different locations depending on sound frequency, stimulating specific auditory nerve fibers.
What is the most common cause of conductive hearing loss?
Impacted earwax.
What is ossicular discontinuity and its causes?
A disruption in the ossicle chain due to trauma, infection, surgery, or tympanic membrane perforation.
What is otosclerosis?
Fixation of the stapes footplate, preventing it from vibrating against the oval window, reducing sound transmission.
How can middle ear fluid affect hearing?
It impedes ossicle vibration and tympanic membrane movement, reducing sound transmission.
What is the function of the eustachian tube?
To equalize pressure between the middle ear and the external environment.
What are the normal functions of the external and middle ear?
Acts as a transformer, converting sound pressure into mechanical vibrations and transmitting it from air to solid matter.
What happens when the external or middle ear is damaged?
It causes conductive hearing loss, leading to elevated hearing thresholds.
What are the normal functions of the cochlea and auditory nerve?
- Transducer (converting mechanical energy into electrical impulses). 2. Coder (processing electrical signals into recognizable sound patterns).
What happens when the cochlea or auditory nerve is damaged?
- Transducer damage leads to distortion (hearing sound but not understanding it). 2. Coder damage leads to adaptation (hearing and understanding but failing to comprehend).
