What parts of the ear does air conduction test?
-all four parts of the auditory system
- outer ear
- middle ear
- inner ear
- auditory nerve
What parts of the ear does bone conduction test?
- Inner ear
- Auditory nerve
What is an air-bone gap?
It is a conductive hearing loss (e.g. middle ear infection) that produces a difference between air and bone conduction
What characterises a conductive hearing loss?
- Air conduction
- impaired
- Bone conduction
- WNL
- Air-bone gap
- yes
- lesion
- outer or middle ear
What characterises a sensorineural hearing loss?
- air conduction
- impaired
- bone conduction
- impaired
- air-bone gap
- no
- lesion
- inner ear or auditory neural system
What characterises a mixed hearing impairment?
- air conduction
- impaired
- bone conduction
- impaired
- air-bone gap
- yes
- lesion
- outer ear or middle ear + inner ear or auditory neural system
What is the NZ audio gram symbol for right ear air conduction?
Red O
What is the symbol for left ear bone conduction?
Blue >
What is the symbol for right ear bone conduction?
Red
What is the symbol for left ear air conduction?
Blue X
vowel sounds are…
Low frequency and high amplitude
Consonants are…
High frequency and low amplitude
What are the first speech sounds often affected by hearing loss?
/f/, /s/, /th/
What are the components of a testing system that need calibration?
- the audiometer
- the transducers
- the test room or booth
What is a sound field
A space in which a wave of sound pressure propagates
What is a free field
A sound field with no obstacles
Categories of impairment
Pruetone average:
-10 to 15 = none 16 to 25 = slight 26 to 40 = mild 41 to 55 = moderate 56 to 70 = moderately severe 71 to 90 = severe >91 = profound
What is the speed of sound in air?
340m per second
What is dB SPL?
Physical description, without reference to humans
What is dB A?
- Compensates for the fact that humans can hear some frequencies better than others
- best for measuring quiet sounds
What is the range of frequencies humans can hear?
20 Hz and 20 KHz
What is the frequency range humans are most sensitive to?
1 and 4KHz
True/false
It takes less pressure to stimulate the ear at lower frequencies than higher frequencies
False
It takes more pressure to stimulate the ear at lower frequencies
What is a fast Fourier transform (FFT)
The way to see the different frequencies that make up a sound
