study guide 2 Flashcards
sound can be defined in 2 ways
- psychological : act of hearing
2. physical : physical movement of air molecules within the environment
a physical phenomenon which describes a movement or vibration of an elastic medium without permanent displacement of the particles
sound
the disturbance of air molecules striking other molecules creates
waves
these waves or vibration of air molecules are what the _______ detects when we hear
auditory system
the _____ of the medium the molecules are in determine the characteristics of the sound
elasticity
characteristics of sound
mass
force
inertia
elasticity
quantity of matter present ; air molecules have ____
mass
a push or pull on an object; has both magnitude and direction
force
the tendency to resist any change in motion
inertia
all bodies remain at rest or in a state of uniform motion unless other forces act in opposition
newton’s first law
______is the tendency of an object’s resistance to deformity and its return to the rest position
elasticity
___ are made up of successive compressions and rarefactions
waves
vibration of sound molecules
compressions
rarefactions
types of waves
transverse
longitudinal
sine
the molecular motion in TWs is perpendicular to the direction of wave motion. i.e. pebble thrown in water
transverse waves
important to understand sound; example would be the motion of wheat blowing in a field
longitudinal waves
used to graphically and mathematically explain a sound wave since it can not be seen. EX of a bucket filled with sand on the end of a string is used in many texts
sine waves
this succession of molecules being shoved together and pulled apart create a motion called
waves
successive compression and rarefactions make up ______
sound waves
number of complete cycles per unit time
frequency
an object’s distance from rest to maximal displacement
amplitude
around of time needed to complete on cycle of vibration
period
timing of compressions and rarefactions of wave
phase
the human ear responds to frequencies between _________ Hz
20 and 20,000 Hz
the frequencies between __________ are the most critical for the perception of speech
300 and 3000 Hz
as the compliance of a body increases the frequency at which the body is most easily made to vibrate
decreases
systems that have more _______vibrate better at high frequencies
elasticity
subjective impression of the power of a sound; the unit of measurement is the sone
loudness
the subjective impression of the highness or lowness of a sound; the psychological correlate of Hz
pitch
length of time
duration
the extent of the vibratory mass from its position of rest to that point furthest from the position of rest
amplitude
how quickly the wave travels from one point to another
sound velocity
velocity of sound in air is
1130 feet per second/ 344 meters per second
the ______ of a sound wave is the speed with which it travels form the source to another point
velocity
the _____the medium, the faster sound will travel
denser
sound travels slower at higher elevation because the ________
air molecules are farther apart ( air is thinner)
as density increases the speed of sound though the material
increases
is the distance between any point on a sine wave to the same point on another cycle of the wave; the distance between two rarefactions or condensations
wavelength
wavelength is inversely proportional to ___
frequency
the study of the relationship between physical stimuli and the psychological responses in which they give
psychoacoustics
ability to determine what direction the sound originated
localization
the reflection of sound from a surface; as this increases, localization ability decreases
reverberation
a sound that is made up of a number of different sinusoides, each with a different frequency; Speech is an example
complex sounds
each mass has a frequency at which it most naturally vibrates ; a body can e set into motion by frequencies other than this
resonance
repeat over time (as in speech or music ) will naturally have a fundamental frequency
periodic sounds
(non repeating sound) will not have a fundamental frequency
aperiodic
in a periodic complex sound, all frequencies are whole number multiples of the fundamental ; tones which occur above the fundamental Hs are called harmonic or overtones
harmonics
the mathematical breakdown of any complex wave into its components parts, consisting of simple sinusoids of different frequencies. the fundamental Hz of the complex wave determine the harmonics
fourier analysis
the sum components of a complex wave
spectrum
a tone of only one Hz
pure tone
highly complex sound, produced by random oscillation, aperiodic
noise
the amount of sound energy per unit of area
intensity
the relationship in time between two or more waves
phase
the intensity of a sound wave
described as decibels (dB)
Is a ratio utilizes a logarithm nonlinear may be expressed in terms of various reference levels, which must be specified is a relative unit of measure
important information about dB
audiologist and acousticians use________ rather than intensity terms
Sound pressure level (spl)
the lowest sound intensity that stimulates normal hearing; different pressure amounts are required to stimulate zero hearing level at different frequencies
hearing level (HL)
the level at which the tone is so soft that it can be perceived only 50% of the time it is presented
threshold of a pure tone
the ability to determine the specific location of a sound source; complex phenomenon resulting from the interaction of both ears
localization
how is localization possible
because of relative intensities of sounds and their times of arrival at the two ears
when two sounds are heard simultaneously, the intensity of one sound may be sufficient to cause the other to be inaudible. this change in the threshold of a sound caused by a second sound with which it coexists is called ____
masking
the noise that causes the interference is called the
masker
resonance characteristics are defined by
impedance
the ______ of a medium is the opposition it presents to the transmission of acoustic energy
impedance
how is hearing measured?
with an audiometer
allows us to select the frequency we want to present to the test ear;
frequency select
allows the user to select the loudness of the tone presented ; typically will range from -10 to around 100 dB HL
intensity (dB hL) Level
allows us to select the type of signal we want to present to the ear; we will select from tone, white noise, narrow band noise, speech, or warbled tone
stimulus type
correct earphone over the correct ear
red on right and blue on left
allows us to choose in which mode the stimulus will be delivered to the patient or test ear
transducer
when activated, enables the audiometer to present stimulus simultaneously through both channels of the audiometer with the depressing of either of the stimulus present buttons
interlock or reverse
this feature allows the clinician to interrupt testing and speak to the patient without changing any protocols on the audiometer or the need to enter the booth
talk-over
allows you to hear the patient while in the sound booth via a microphone
talkback
speech can be delivered to the patient either by live voice, tape, or CD presentation; live voice requires the least amount of time;
tape recordings provide for the highest degree of reliability and accuracy
speech stimulus
used to measure sound pressure levels in the environment
sound level meters
