AUD6400 Estimating Thresholds, Signal Detection, and Critical Band

What is minimal audible pressure?

threshold measurements made via earphones (monaural)

What is minimal audibility field?

Threshold measurements made in soundfield (binaural)

What are frequency effects?

minimal detectable SPL varied as a function of frequency

What does frequency effect show?

higher SPL needed for detection at very low and very high frequencies

What are degrees of hearing loss?

normal, minimal, mild, moderate, moderately severe, severe, profound

What are different configurations of hearing loss?

sloping, rising, precipitously sloping, notched, flat, cookie bite

What are the types of hearing loss?

sensorineural, conductive, mixed

What is signal detection theory?

used to assess a patient’s ability to discriminate whether a stimulus was heard or not, or if there is a difference in intensity

What is auditory sensitivity?

how well/poorly the ear responds to sound

What is response proclivity?

how the listener responds to the stimuli

What is response bias?

listener’s tendency to say yes

What is neutral response bias?

no bias, will have the highest number of correct detections

What is conservative response bias?

listener has strong tendency to not respond than to say yes, fewer false positives, fewer true positives

What is liberal response bias?

listener is more likely to say yes, many false positives

What is reaction time?

time elapse between the presentation of a stimulus and the patient’s response

What is masking (psychoacoustics)?

process by which the presence of one sound interferes with the perception of another

Which hierarchy of hearing is masking typically applied to?

can be applied to all; detection, discrimination, recognition, and comprehension

What is simultaneous masking?

when a signal and masker completely overlap

What type of masking noise isn’t typically used?

tone as masker, creates false positives

What are the two types of masking?

energetic and informational

What is energetic masking?

when energy of masker competes directly with energy in a signal, used more for peripheral auditory system evaluations

What is informational masking?

masker perceptually competes with the signal, may cause uncertainty when in competition with a signal, used more for central auditory evaluations

What factors affect masking?

power of masker compared to signal and frequency characteristics of masker compared to signal

What is white noise?

small random amplitudes over time, comprised of frequencies of human range of hearing

What is narrowband noise?

band-restricted version of white noise, does not contain all frequencies heard by humans

What is narrowband noise characterized by?

bandwidth, center frequency, and level per cycle

What are filters?

modify sounds by attentuating or increasing certain frequency components of a stimulus

What are the four major classes of filters?

low-pass, high-pass, band-pass, band-reject

What are low-pass filters?

allows low frequencies while attenuating high frequencies

what are high-pass filters?

allows high frequencies to pass and attenuates low frequencies

What are band-pass filters?

allows frequencies in specific region to pass

What are band-reject filters?

attenuates frequencies within a specific range and allows all others to pass

What kind of filter is frequency selectivity?

band-pass, allows certain range of frequencies to pass

Where is masking greatest?

at signal frequencies nearest frequency encompassed by masker

What is upward spread of masking?

more masking occurs at signal frequencies higher than the masker than at signal frequencies lower than the masker, low frequency sounds mask higher frequencies more

What hearing loss is most affected by upward spread of masking

SNHL causes a reduction in frequency selectivity meaning a greater upward spread of masking

What is the critical bandwidth for masking pure tones?

frequency range centered around pure tone being tested

What is central masking?

when masking noise causes elevation in TE threshold, greater at high frequency tones