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Exam 4 Speech Science

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Terms

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adjacent speech sounds that
require the same articulator use a single
articulatory gesture for both sounds
assimilation
"I miss you", the /s/
and /j/ phonemes both require particular
articulations of the tongue tip and blade, so the
/s/ is often produced with the palatal gesture of
the /j/, resulting in a // sound (and similar
sequenc
example of assimilation
adjacent speech sounds that
use different articulators can be overlapped in
production (two articulations simultaneously)
coarticulation
For example, the /s/ does not require the use of
the lips, so lip rounding in an adjacent sound
(like /u/) can begin during the /s/ (compare
"seat" and "suit", similarly for "tea" and "two")
–
example of coarticulation
Variation in the degree to which the articulators
reach their "ideal articulatory goals" is referred
to as degrees of
hyperarticulation and hypoarticulation
very careful
pronunciation
hyperarticulation
pronunciation that undershoots the target
hypoarticulation
do not
achieve the extreme articulations that they
would if produced in isolation as in rapid speech
corner vowels
Assimilation or coarticulation can create an
acoustic result for an articulation that is
different from what is produced in isolation. In many cases, the combined articulation
reflects information about the two (or more)
sounds that a
what happens to acoustics of context effects and their affects on formants?
As articulatory positions change, the resonating
frequencies of the vocal tract change. Changing resonant frequencies in the vocal
tract result in transitions in the formants of
vowels and resonant consonants. Formant transitions in neighb
explain formant transitions
F1: expected to be rising following release
for all stops due to lowering of the
jaw/tongue. F2 & F3: differences following release
expected for different places of articulation. /b/ : F2 & F3 rise due to release of lip rounding /d
explain changes in f1, f2, etc in formant transitions for b, d, and g.
Coarticulation most noticeable for sounds
that are
adjacent (next to one another)
effects of coarticulation for
sounds 2 or 3 phonemes away depending on
the speech rate and the particular
articulatory configuration
There can be effects of coarticulation for
sounds 2 or 3 phonemes away depending on
the speech rate and the particular
articulatory configuration. Start of low F3 during the
initial vowel in "every")
every is an example of
aspects of production
that carry over more than one segment
“Over” segmental
found when two different articulators overlap their productin
coarticulation
when producing the common phrase "is she going?", the loudest fricative noise for the /z/ phoneme in "is" is lower than expected, b/c the tongue blade constriction is father back on the palate than it would normally be. This is an exa
assimilmation
when producing the common phrase "is she going?", the loudest fricative noise for the /z/ phoneme in "is" is lower than expected, b/c the tongue blade constriction is father back on the palate than it would normally be. this effect wo
anticipatory
I am talking to a hearing-impaired adult who is having trouble understanding. I make an extra effort to be understood for the word "dog." In looking at this production, I find that the /a/ is "dog" has a higher F1 than it would normal
hyperarticulation
the ____ scale is special scale used to model the way the ear processes frequency.
Bark
most of the amplification of sound that occurs in the middle ear is due to ______.
the difference in SA b/w the tympanic membrane and the oval window
differences b/w frequiences at ___________ are easier to hear
low frequiences (20-1000 Hz)
what difference in frequenies is the eaiest for a listener to perceive?
differences b/w high vowels and low vowels
from studies of listeners' perception of acoustic properties of speech sounds, which formants are more important for vowel identification
f1 and f2 are more important than f3 for vowel identification
Stress
Intonation
Duration
Juncture
examples of suprasegmentals
get exaggerated
when talking to children/animals or in
“clear” speech.
Stress
Intonation
Duration
Juncture
as do artic. positions -->
formant diffs
Tells which syllable of a word or sentence
is most important.
stress
sometimes tells whether word is a
noun or verb
lexical stress
english does what to syllables?
alternation weak and strong...can tell difference between verb and noun aka lexical stress
primary, secondary, unstressed
what are the 3 levels of lexical stress?

what type of coarticulation is going on here?
"I miss you", the /s/
and /j/ phonemes both require particular
articulations of the tongue tip and blade, so the
/s/ is often produced with the palatal gesture of
the /j/, resulting in a // sound (and similar
sequences are found with other alveolar and
palatal combinations, like in "did you")

what is going on here in the /s/ in both words?
Coarticulation- the /s/ does not require the use of
the lips, so lip rounding in an adjacent sound
(like /u/) can begin during the /s/ (compare
"seat" and "suit", similarly for "tea" and "two")

explain the formant differences b/w ba, da, and ga.
F1: expected to be rising following release
for all stops due to lowering of the
jaw/tongue.
• F2 & F3: differences following release
expected for different places of articulation.
– /b/ : F2 & F3 rise due to release of lip rounding
– /d/ : F2 & F3 flat of fall (point to high freq.)
– /g/ : F2 & F3 move apart (point to mid freq.)
• For all – greater formant movement
expected for greater articulatory movement
(varies depending on the vowel context)
special case to distinguish from
a similar word
Contrastive
Stressed syllables: typically longer in
duration, higher in F0, and greater intensity
than the same syllable in non-primary stress
position.
explain the effect of stressed syllables acoustically
Vowel reduction: many vowels reduced to
schwa when in unstressed position, but you
see full vowel when put in more stress
position.
explain the effect of vowel reduction acoustically
what creates stress?
increase vocal effort
Tells us about a talker’s emotional state,
overall meaning of a sentence, whether
done talking or not.
intonation
rise-fall
(declarative sentence, non yes/no question),
fall (emphasis, short unemotional), rise
(yes/no question, not finished)
what are the three general contours?
what is important formantin contours?
F0
Different speech sounds differ in duration, even
when in the same context (e.g., tense and lax
vowels). (look at some). This helps talkers
identify the vowel (especially in noise).
explain intrinsic duration.
vowels tend to be
longer before voiced than before voiceless
stops (helps because final stops often
unreleased)
how does duration change vowels?
relates to pronunciation depending
on location of syllable boundaries
juncture
when a __________ is
between two _______ you can tell what
syllable/word it “belongs” to
when a consonant is
between two vowels you can tell what
syllable/word it “belongs” to
when you cannot tell where a consonant belongs to?
ambisyllabic
“patty” vs. “party”
example of ambisyllabic
How is sound produced differently to show
where word juncture is?
It sprays, worth less, how to wreck a nice
beach.
pinna to tympanic membrane
outer ear
Protection, resonator, and localization
function of outer ear
tympanic membrane to oval
window (including 3 ossicles)
Middle Ear
-Conversion of sound from pressure variations
to mechanical vibrations; amplification (lever
action and decrease in surface area).
– Acoustic reflex (stapedius m.); pressure
equalizing.
function of middle ear
fluid filled space (coiled)
with access to middle ear via oval and round
windows
inner ear aka cochlea
Pressure variations in fluid cause vibration of
basilar membrane (more depending on frequency –
basal end --> high frequency; apex end --> low
frequency).
explain the effect of pressure of fluid in the ear
contains hair cells and support cells
orgin of corti
contact b/w
tectorial membrane and hair cells causes nerve fiber
stimulation
what does contact with tectorial membrane cause?
Different hair cells (& nerve fibers) for different
frequencies, depending on place (also in cortex)
explain about hair cells and frequencies
when is hearing is
less sensitive to small changes in frequency or
amplitude?
at higher frequencies or amplitudes
Hearing becomes habituated to a steady sound,
and is more sensitive to dynamic (changing,
varying) sounds.
how is hearing affected by steady and dynamic sounds?
Frequency and amplitude scales for hearing
are (approximately) __________
logarithmic
The higher the frequency or amplitude, what to make it audible?
The higher the frequency or amplitude, the
larger a change in frequency or amplitude needs
to be in order to be audible
Special frequency scale
bark
Special amplitude scale
db
how to spectrograms display amplitude and frequency?
Spectrograms do display amplitude in dB, but
usually do not display frequency in Bark.
Non-linear frequency in hearing comes in
part from the structure of the
basilar membrane
Range of hearing is 20-20,000 Hz
– About 1/3 of the basilar membrane for the
lowest 1000 Hz of hearing (or 5% of range) -
apex to 3rd cochlear turn
– Remaining 2/3 of the basilar membrane for
1000-20,000 Hz (95% of range)
explain about hearing and the basilar membrane
Also, hair cells tend to be less densely
distributed at the basal end.
how are hair cells distributed on basal end of baslar membrane?
While the dB scale does approximate nonlinearity
in perception of amplitude, it does
not reflect the differential sensitivity of the
ear at different frequencies
what does and doesn't the db scale do?
the ear canal amplifies sounds in
the
3000-5000 hz
what do spectrograms do to reflect the differential sensitivity of the
ear at different frequencies?
use “pre-emphasis”, raising
the amplitude by 6 dB/octave, to reflect this
sensitivity somewhat (not specific enough)
Hearing is based on the firing of auditory
nerves, which can habituate
habituation
After a nerve is fired, its action potential is
depleted and it is more difficult to make it fire
again
– As a result, the neural response to a steady,
unchanging stimulus diminishes in strength
over time
The stapedius mus
explain habituation
the most
useful parts of the spectrogram
long, steady state portions like stressed
vowels and strident fricatives
know Spectrograms vs. Cochleagrams
know Spectrograms vs. Cochleagrams
Computer simulations of the function of the
cochlea
cochleagram
reflects the actual
output of the auditory nerve to the brain
better than a spectrogram does
what do cochleagrams reflect?
which are easier to derive cochleagram or spectrogram?
spectrogram
shown researchers
what acoustic features are characteristic of
certain categories of sounds
acoustic cues
the regularities that have
been shown to actually be used by listeners
acoustic cues
are regularities the same for everyone?
NO!
cues don’t vary over a continuum
in real speech (people don’t produce “in
between” sounds)
problem with studying acoustic cues
One (or more) acoustic
properties are varied in steps from what is
typical for one phoneme to what is typical
for another phoneme
continum
syllables are presented one at a time;
listeners must decide which sound they
heard from among a small number of
alternatives
identification
sounds are presented in
pairs; listeners must decide whether sounds
are same or different.
discrimination
slide 20 acoustic cues throug 22...in hearing and speech perception lecture
slide 20 acoustic cues throug 22...in hearing and speech perception lecture
Some cues were clearly found to be more
important than others for some phonemes
primary cues
most potential cues have been
found to be useful if others not available
secondary cues
computer processing
of speech
Speech processing
applications of speech
processing (programs and devices for
many purposes)
Speech technology
producing intelligible
speech via commands to a machine
Speech synthesis
identifying
phonemes or words via machine
Automatic speech recognition
take written text and
convert to speech that is easily recognized
by listener
purpose of speech synthesis
Text-to-speech
tts
morphology, syntax & prosody (affect how
words are spoken – stress, phrasing, etc.)
• print to phonetic symbols (spelling rules)
• phonetic symbols to acoustic productions
(acoustic cues & coarticulation effects)
what are the major tasks of speech synthesis?
uses sourcefilter
theory of speech production to create
a source sound and filters that can be
changed to create desired acoustic output.
– Rules for individual phonemes
– Rules for phoneme to phoneme transitions
(coarti
explain formant synthesis by rule
Small storage needs (computer program) for any
number of voices (pos)
• Requires a lot of background knowledge (neg)
– Must develop rules for each phoneme and transition
to every other possible neighboring phoneme (neg)
– M
what are the pros and cons of formant synthesis?
uses natural
speech segmented at areas of “less
variability” including diphone and demisyllable
Concatenative synthesis
phoneme center to phoneme center
diphone
syllable onset to nucleus or
nucleus to end
demisyllable
– Must store every possible combination as a
separate file for each voice used (neg).
– Prosody may be too unvarying / breaks (neg).
– Hard to speed up appropriately (neg).
– Relatively easy to create (pos).
what are the pros and cons of concatentative synthesis?
speech synthesis application for for speech impaired
(autistic, dysarthric, etc.)
AAC (augmentative & alternative
communication)
why do blind like formant synthesis?
(formant
synthesis better because they like up to
600 wpm
type of speech synthesis for blind
Screen readers
Voice response systems (phone/car/etc.)
⬢ Other automated, repetitive tasks (weather
reader)
⬢ Toys (Speak-n-Spell)
⬢ Create stimuli for research.
are examples of
speech synthesis applications
Alternative approach to formant synthesis. Parameters are based on acoustic
consequences of articulatory positions.
Articulatory synthesis
⬢ Impossible combinations are not allowed,
unlike for formant synthesis (pos)
⬢ Not enough knowledge for it to work well
yet (need more imaging of tongue, etc.
and mapping to acoustic outputs).
what are pros and cons of articulatory synthesis?
Use of computer program to take acoustic
input and identify words/phonemes.
Automatic Speech Recognition
Different from speech understanding
Automatic Speech Recognition
– Digitize speech input
– Identify acoustic features in input (may
correspond to different phonemes).
– Select word/phoneme with most matching
features.
major steps of automatic speech recognition
Requires all our knowledge about how
listeners identify speech sounds. Still not
as good as human listeners.
automatic speech recognition
• Easier if words are separated slightly so
that system knows where they are (human
listener doesn’t need this).
• Variability is a big challenge: must
recognize “same” sounds in different
contexts/different talkers as
what are some Speech Recognizer Issues?
words must be separated by 500 ms
or more
isolated
words must be separated by only
short pauses
connected
no pauses needed – accepts
normal conversational speech.
continuous
another word for connected
Dragon system
200 words or less
small vocab
200-1000 words
large vocab
1000 + words to 20,000 words
vary large vocab
needs to be trained for
each new talker
speaker dependent like cell phone
can recognize any
talker (constrained usually by dialect, voice
quality). Much harder, esp. for high accuracy.
speaker independent
phone system
(needs speaker independent, but small
vocab. often okay) – menu systems
Voice response systems
typing by voice for mobility
challenged or to avoid overuse injuries
(Dragon Naturally Talking). Also for
hearing impaired.
Speech to text
decides whether talker achieved goal or
not.
Computer-Based Speech Training Aids
drive system
selected
goals and populatione
designed to be used in conjunction
with a speech pathologist.
– Small vocabulary, speaker dependent
– Speech of children with speech delay is too
variable for speaker independent.
– Needs multiple goals to avoid frustration
explain ISTRA
speaker independent; language specific.
hearsay
Want to understand what speech cues
listeners use and whether different groups
use them differently.
– Understand how language is
processed/learned by normal listeners.
– Understand differences/disorders.
– Create bett
purpose of speech perception experiments
– Type of experiment (identification or
discrimination)
– Type of stimuli (synthesized or natural).
How to study speech perception?
⬢ Specify what formant frequency values
should be (either unchanging or must
specify each point in time).
⬢ Source is created, goes through filters,
output is a file. Create a new file for each
stimulus.
how to use Synthetic Speech for
Research?
⬢ Observed: CV and VC formant transitions
vary depending on place of articulation of
stops.
⬢ Question: Do listeners use it?
⬢ Stimuli: vary onset of F2 for transition from
consonant to vowel (CV) from steeply
rising (
explain Consonant place of articulation
experiments
Identification: Play each stimulus: three
choices (bae/dae/gae).
• Analyze data: typically people are very
sure for most stimuli – high percent
identification. 1 or 2 stimuli at 50%
• This means steep identification functio
explain Place of articulation experiments
Category boundary:
where the function of
identification is at 50%.
play pairs of stimuli. Some
two steps apart; some exactly the same.
Task is to say same or different.
Discrimination
when you get typical results for place articulation experiments
good discrimination only when
two stimuli identified as different phonemes--baffeling result b/c physical differences are equal across all
steps
The combination of steep identification
functions AND good discrimination only at
category boundaries
categorical perception
• Create a continuum by varying both F1
and F2 to go from /I/ to /E/ to /ae/.
– Same type of id. and discrimination tasks as
for consonants, but very different results
– identification function NOT steeply sloping
– Fairl
explain vocal experiments
way to explain categorical
perception
Motor Theory of Speech Perception
we identify phonemes through
access to the underlying motor gestures that
produced them, not directly through acoustic
features (innate and special for humans).
Motor Theory of Speech Perception
invariance exists (just need to do more
research) and speech system developed
on existing auditory sensitivities.
Alternative Theory: Acoustic Invariance
Support: infants apparently born with
categorical perception.
⬢ Support: sort of avoids problem of
variability (gestures are consistent?).
⬢ Problem: some non-human animals seem
to have categorical perception.
⬢ Altern
alternative to motor theory
steeper slope
stop
gentler slope
vowel
are things that can change alot
dipthongs
perceptions drives production --> phonemes --> word
perceptions drives production -->
uses natural speech synthesis and higher storage space
cognitive synthesis
steeper the slope the
faster articulators moving
computer speech programing
formant synthesis
very unnatural sounding
isolated
alters input
cochlea
doesn't drop dramatically
pitch
relates to pronunciation and how it changes to syllable boundaries
duration
smaller bone in the human body
stapes
fewer HCs designated to higher frequencies than low
explain nonlineary in hearing
f3 and f4 on coch merge together; see f1, f2-f4 together, then f5
what is a big difference b/w coch and spectro?
what is poor for formant synthesis?
fricatives and stops
___ db loss from ossicles missing
30 db loss
____ db loss of SA from oval window to TM
25 db loss
____ db loss b/c of stapedius
5 db loss
tm=.85cm2
ow=.03cm2
surface area of tm and ow
higher sa lower pressure
lower sa higher pressure
realtionship b/w sa and p
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