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