Loudness Perception

Do two tones at the same intensity but different frequency sound the same level of loud?

No

Define loudness

perception of the physical parameter

True or false: loudness is related to sound intensity

true

Define intensity

physical parameter

Fill in the blank: loudness does not equal _________

intensity

What factors can affect loudness?

intensity, frequency, bandwidth, and duration of sounds

Name the ways to measure loudness

rating/scaling method, matching method, categorical loudness scaling, and intensity discrimination

Define the rating/scaling method

measures how loudness changes with intensity

Name some examples of rating/scaling method

magnitude estimation or production

Define matching method

measures how loudness changes with frequency

Name examples of matching method

loudness balancing

Name some examples of categorical loudness scaling

UCL and MCL

Name some examples of intensity discrimination

just noticeable difference

Name the ways loudness and intensity are measured

rating method and stevens’ power law

Define rating method

magnitude estimation or production that can be obtaining loudness growth function

What unit of loudness is used in rating method

sone

Fill in the blank: 1 sone is equal to _____________.

the loudness of 1 kHz tone presented at 40 dB SPL

Sone is equal to how many phons?

40

Fill in the blank: sone scale “___________” frequency

ignores

Define stevens’ power law

loudness is related to the intensity to the intensity of sound

What is stevens’ power law formula?

loudness = KI^e

In stevens’ power law, what is the relationship loudness and intensity at an exponent of 1?

loudness and intensity grow at the same rate

In stevens’ power law, what is the relationship loudness and intensity at an exponent less than 1?

loudness grows slower than intensity

In stevens’ power law, what is the relationship loudness and intensity at an exponent above 1?

loudness grows faster than intensity

What is the average of stevens’ power law?

~0.6

Fill in the blank: loudness doubles with a ____ dB increase in intensity

10

Fill in the blank: a power function relationship when ____ are plotted on a log scale with either phons or ___ _______.

sones ; dB SPL

In stevens’ power law the line on the graph is not what?

a continuous straight line

Fill in the blank: stevens’ power law, sound will vibrate more _______ linearly at louder intensities

rapidly

The loudness growth pattern resembles what in audiology?

the cochlear basilar membrane vibrations

In loudness and frequency, at 1000 Hz phons are the same as what?

dB SPL value

What is the perceptual unit used in loudness and frequency?`

phons

Name the way loudness and frequency are measured?

equal loudness contours

Define equal loudness contours

curves that show the relation among phons, decibels, and frequencies

Fill in the blank: equal loudness contours, mid frequency sounds are ______ than low and high frequency sound

louder

Fill in the blank: pre-dominantly the equal loudness contours are determined by our ____ and _______ ear characteristics

outer ; middle

What do low loudness levels resemble?

minimum audible field curve

At high loudness levels, equal loudness contours become what?

flatter

What is the phon level at A-weighting?

40 phons

What is the phon level at B-weighting?

70 phons

What is the phon level at C-weighting?

100 phons

What is the phon level at Z-weighting?

0 phons

Define decibles

objective measure of intensity of sound

Define phons

subjective measure of loudness of sound

1 phon is equal to what dB?

1 dB at 1000 Hz

Phons change with what?

frequency

Define sones

subjective measure of loudness of sound that doesn’t change with freqeuncy

1 sone is equal to how many phons?

40

Fill in the blank: doubling in loudness will have a 10 _____ increase in a sound level

phon

True or false: loudness does not depend on bandwidth

false

Loudness increase results in what?

increasing bandwidth

Fill in the blank: the same dB SPL level, wide bandwidth stimuli are louder than ________ bandwidth stimuli

narrow

Define loudness summation

an experiment that compares the loudness of a two-tone complex with a standard tone

What was the result of the loudness summation experiment?

loudness perception of two-tone complex and noise bands was the same as the tones and noise were within the same critical band

What is the relationship between loudness and duration?

the longer the sound, the louder it is (only up to a few hundred milliseconds)

What will happen when we keep presenting a signal for a long time?

the signal will become softer due to loudness adaptation

Name some characteristics loudness adaptation

high inter-subject variability

adaptation effect is the same for monaural and binaural input

adaptation effect increases with frequencies

more adaptation is present for low level sounds compared to high level sounds

Name the different ways differential sensitivity is measured in loudness?

intensity discrimination

just noticeable difference in intensity

weber’s law

How is intensity discrimination?

difference in intensity

Define just noticeable different in intensity

the smallest difference in intensity that can be discriminated by the ear

Define weber’s law

the change in a stimulus that will be just noticeable is a constant ratio of the original stimulus

What is another name weber’s law?

weber’s constant

What is the formula for weber’s law?

difference stimulus/stimulus = constant

Name the three ways to report just noticeable in intensity

difference in intensity

weber fraction : difference in intensity/intensity

dB difference or difference in loudness

Define difference in intensity

difference in intensity increases with the increase of stimulus level

Define weber fraction

ratio of smallest detectable change in magnitude of the quantity

Define the dB reported difference

change in dB that can just be noticed and the dB difference between sounds

What is the equation for the difference in loudness?

L = 10 log (I₂/I) = 10 log (I + difference I / intensity) = 10 log ( [difference I / I] +1 )

True or false: difference in loudness can never be negative

true!

Fill in the blank: Weber’s law only holds true for _____ levels

some

Define the effect of broadband noise in relation to weber’s law?

weber’s law held only at moderate to high levels

Define the effect of narrowband - pure tones in relation to weber’s law?

weber’s law did not hold

weber fraction decreases with increasing levels

near miss to weber’s law

weber fraction was not dependent on frequency

Define the characteristics of near miss to weber’s law

more region of BM is stimulated

wider spread of excitation

AN fibers tuned for frequencies lower and higher than center frequency in intensity coding

more neurons are utilized which can represent the intensity more accurately

better discrimination at louder intensity

What is the method used in loudness perception and hearing disorders?

categorical loudness scaling

Categorical scaling is seen in which clinical procedures?

MCL, UCL, and LDL

What is seen in loudness perception in SNHL?

abnormal loudness recruitment which causes rapid growth of loudness

higher threshold

True or false: those with SNHL and NH have similar UCL

True !

In those with SNHL, the loss of OHCs leads to what?

threshold elevation

no cochlear amplifier

loss of compression

more linearity in the BM

Define hyperacusis

hypersensitivity to sounds that are moderately loud

Name characteristics seen hyperacusis patients

reduced tolerance to suprathreshold sounds

typically not related to recruitment

Fill in the blank: both SNHL and hyperacusis _____ input dynamic range

reduce

What does this show?

rating method

What does this show?

intensity discrimination

What does this show?

difference in intensity

What does this show?

weber fraction

What does this show?

reported dB difference

What does this show?

loudness perception in those with HL

What does this show?

loudness perception in those with hyperacusis

Fill in the blank: magnitude estimation or production is typically used to measure how loudness changes with ________.

intensity

Fill in the blank: loudness typically doubles with a __ dB increase in intensity.

10

Fill in the blank: at 1000 Hz, 60 dB SPL is equal to _____.

60 phons

Fill in the blank: a sound level meter with a dB (B) weighting scale uses the ______ phon curve.

70

Fill in the blank: at 1000 Hz, 30 dB tone may sound _______ after being presented for more than 5 minutes.

softer

Fill in the blank: abnormally rapid growth of loudness is termed _________ ________.

loudness recruitment