exam 1 Flashcards
Sound is a ______ ______
pressure wave
what is the smallest amount of pressure required to move an eardrum
0.0002 dynes/cm2
Velocity
- The speed of a sound wave
- Impacted by elasticity and density
Wavelength
-Distance a sound wave travels in one cycle
Pure Tones
- A single, isolated pitch
- “simple sound”
- very rare
- can be heard from tuning forks and audiometers
Complex sound
- Two or more pitches combined
- so pretty much everything else
Those who wear hearing aids sometimes report that on __________ days they are able to hear ___________.
- humid/muggy
- more clearly
Longitudinal waves
-Movement in one direction
Transverse waves
-Perpendicular movement
________ and _______ are points of maximum displacement
Compression
Rarefaction
The number of cycles per second is called:
Hertz
Hertz
Pitch/frequency
Subsonic:
-Less than the speed of sound
Supersonic:
-Greater than the speed of sound
Other types of sound
- Infrasonic
- ultrasonic
Decibels:
- The amplitude of the cycles
- loudness
Humans hear from __ Hz to _____ Hz but we only test to ___ Hz
- 20Hz
- 20,000 Hz
- 8K Hz
What is the range of Hertz needed for human speech?
Between 500 Hz and 4000 Hz
The period of sound:
- Hertz/frequency/pitch
- cycles per second (cps)
Low frequency sounds = _____ period
longer
High frequency sounds = _____ period
shorter
The human ear is most sensitive from :
125 to 8000 Hz
needs the least dynes per cm2
dB SPL=
- Sound Pressure Level
- used in measuring hearing aid performance/function
- 0.0002 dynes/cm2
dB IL =
- Intensity Level
- used in electrical measurements/calibration of audiometers
- watts/cm2
dB HL =
- Hearing Level
- used on hearing tests and audiograms
- each frequency calibrated to the human zero
dB SL =
- Sensation Level
- refers to the level above threshold
- used for speech recognition testing
dB nHL =
- Neural Hearing Level
- used in auditory brainstem testing
- most often referred to as eHL (estimated hearing level)
zero on an audiogram is…
NOT the absence of sound, it is the typical lowest hearing level
What is the logarithmic scale used for measuring hearing?
dBHL
The human ear can detect ________
0-140 dBHL
once you reach above this level it results in instantaneous hearing loss
True or false:
Some people can hear negative dB levels.
True
If needed, what is the max level of dB that can be tested?
120 dBHL
What are the measured aspects of an audiogram?
- frequency vs intensity
- air conduction vs bone conduction
- left ear vs right ear (symmetrical vs asymmetrical)
- masked vs unmasked
An audiogram is an _____ graph in which frequency and pitch goes up by ______ on the ___ axis and loudness and intensity goes up by ____ on the ___ axis.
- inverse
- octaves
- x axis
- tens
- y axis
Name the types of hearing loss
- Conductive
- Sensorineural
- Mixed
- unilateral/bilateral
- symmetrical/asymmetrical
- Vibrotactile
- Auditory Neuropathy
Conductive hearing loss:
- outer or middle ear “conducts” sound to inner ear
- can be due to wax, infection, no outer ear, etc.
Sensorineural hearing loss:
- dealing with the cochlea (sensory)
- dealing with the nerves (neural)
Vibrotactile hearing loss:
-sound that you can physically feel because it is so loud and low
Air conduction audiology symbols:
0=right ear (right round) unmasked X= left ear unmasked ∆= masked right ac □= masked left ac ac=air conduction
Bone Conduction audiology symbols:
= left ear unmasked
(open end points to the ear it represents)
[ = masked right bc
] = masked left bc
a symbol with an arrow attached means NR (no response)
Masking:
-Using noise to occupy one ear while testing the other
more symbols:
s = sound field (speakers) both ears working together R= aided right ear only L= aided left ear only CI= cochlear implant
Degrees of hearing loss as described on an audiogram:
- flat vs sloping
- cookie bite (high on the ends low in the middle)
- ski slope (very steep)
- reverse slope (very rare)
- high frequency (looks like a flipped letter L)
Articulation index: most speech frequencies occur between ___ and __
1K and 4K
Acoustics:
-The study of sound and perception
Noise:
-Any unwanted/interfering sound
Signal:
-The sound you want to listen to
Reverberation:
- Echo
- the amount of time it takes a sound to decrease by 60 dB after the source has stopped, measured in seconds
Signal to noise ratio S/N:
-Volume of the signal vs the volume of the noise
General noise tends to carry a lot of ___ _______ which “mask” softer ____ ____ speech sounds.
- low frequencies
- high frequencies