acoustics Flashcards
True/False: sound propagates though air or another medium and can propose through a vacuum?
False: it cannot propagate through a vacuum (pg.48)
areas of higher density and pressure are called ares of _______ and areas of lower density and pressure are called areas of ______
condensation and rarefaction (pg.48)
a sound’s ______ is a count of the number of repetitions of a cyclic patter in 1 second
frequency (f) (pg.48)
what are the most common measurement units of sound?
Hertz (Hz) and kilohertz (kHz) (pg.48)
True/False: periodic sounds have a frequency but aperiodic sounds do not
true (pg.48)
frequency is perceives as what?
pitch (pg.48)
what are intervals between sounds?
semi tones (pg.48)
how many semitones are in an octave?
12 (pg.48)
what is an octave?
a doubling of frequency (pg.48)
what is the duration of one cycle referred to?
period (T) (pg.48)
True/False: frequency and time have an inverse relationship?
true (pg.48)
what is the physical measure of extent of vibrational change from resting position
amplitude (pg.48)
what is the peak amplitude?
the maximum pressure reached by the pressure wave
what is the root mean square amplitude?
root mean square amplitude (pg.48)
what is the power of a sound over a particular area?
intensity (pg.49)
what is intensity measured in?
watts (pg.49)
amplitude and intensity are both measured in…
decibels (dB) (pg.49)
what is the quietest sound that can be heard?
0 dB (pg.49)
amplitude and intensity are both measured in…
decibels (dB) (pg.49)
amplitude= dB-SPL intensity= dB- IL
what is a pascal?
the cute little lizard from tangled… Just kidding it is the measure of units of pressure
(pg.49)
physical measures of amplitude and intensity are perceived as what?
loudness (pg.49)
human hearing is most sensitive to sounds between __ and __
2 and 4 kHz (pg.49)
what is the length of time a sound continues?
duration (pg.49)
what is the distance travelled by a sound during a single cycle?
wavelength (pg. 49)
_______ is the location of a particular point in a waveform cycle relative to the zero line.
Phase (pg. 50)
what shows variations in amplitude, pressure, or intensity of a sound over time?
waveforms (pg. 50)
A waveform can be used to find the exact fundamental frequency, measuring time related cues (VOT), determining whether a sgnal is aperiodic/periodic,, pitch contours & voice quality analysis. T or F?
True (pg. 50)
______ show regions of high amplitude energy and changes over time and is the most frequently used tool in speech analysis.
Spectograms (pg. 50)
Sinusoids consist of a _______ called simple sounds or _______.
single frequency; pure tones (pg. 52)
In the human voice, harmonics are ______.
inifinite (pg. 54)
_________ complex periodic sound produced by vocal fold vibration. (AKA as phonation or voicing)
glottal source( pg. 55)
Vocal folds vibrate conitnously during voiced obstruents. T or F?
False; VFs often DO NOT vibrate continuously during voiced obstruents (pg. 55)
Harmonic amplitude ______ as harmonic freuqency ______.
decreases/ increases (pg. 55)
What is determined by rate of vocal fold vibration?
Vocal pitch (pg. 56)
what are changes in fundamental frequency perceived as?
intonation (pg.56)
in many east asian and African languages, pitch is what?
phonemic i.e. it can change word meaning
they are referred to as tonal languages
e. g. mandarin and all other Chinese languages
(pg. 56)
some languages have a restricted tonal system called _____
pitch accent (some scandinavian and Japanese) pg.56
pitch accent systems usually have only 2 tones, high and low
true/false: languages use voice quality in different ways
true (pg.56)
what is produced when there is a sudden release of air pressure that has built up behind a blockage?
stop consonant bursts (pg.56)
True/False: In english, clicks are speech sounds that have meaning?
False: Clicks are not speech sounds but can still have meaning (e.g.. click is used to mean “giddy-up” to a horse
(pg.56)
True/False: clicks are not used in any languages to convey meaning?
False: clicks are uses as phonemes of speech in some african languages
(pg.56)
what sounds have longer duration than impulse noises where molecules are set into turbulent motion by forcing air through a narrow channel or against an obstruction such as teeth?
continuant obstruents (fricatives) (pg.56)
what do fricatives (obsturents) always include?
aperiodic noise as a sound source (pg.57)
aperiodic noise is the only sound source?
voiceless obstruents (pg.57)
aperiodic noise combined with vocal fold vibration
voiced obstruents (pg.57)
what is the acoustic theory of speech production?
states that speech is produced by passing a sound source through a sound filter (pg.57)
what is the most common sound source?
vocal fold vibration (pg.57)
turbulent and impulse noise also act as sound sources for speech
_______ acts a a filter and modifies sound input
supra laryngeal vocal tract (SLVT)
sounds gain about ____ dB per octave in amplitude as they resonate from the lips
6 (pg.58)
combining different ________ with different filter functions produces all of the sounds of speech
source functions (pg.58)
what are the functions of the filters?
- oral and pharyngeal cavities change size and shape
- sometimes includes airflow through h nasal cavities
- frequencies that resonate in the supra laryngeal vocal tract cavities are a function of cavity size
(pg.58)
_____ cavities have deeper resonating frequencies
larger (pg.58)
____ cavities have higher resonating frequencies
smaller (pg.58)
effect of the supra laryngeal vocal tract
changes amplitude of sinusoids that pass through it
True/False: sinusoids that exit the SLVT have exactly the same frequencies as sinusoids in the inputs
true (pg.58)
True/False: SLVT can add, delete or change the frequencies of component sinusoids?
false: SLVT CANNOT add, delete or change the frequencies of component sinusoids
(pg. 58)
_______- filter envelope shows peaks and valleys
resonant sounds
for example, vowels and resonant consonants
(pg.58)
what are resonant frequencies called?
formants (pg.59)
True/False: Location of resonant frequencies is a function of SLVT shape
True: (pg.59)
- sinusoids at or near formant peaks gain amplitude as they pass through the filter
- sinusoids within valleys of the filter function lose amplitude as they pass through the filter
_____- filter envelope may be a high-pass or band-pass filter
obstruent sounds (pg.59)
example- frication noise, stop bursts, aspiration noise
what position of the SVLT creates the shape for the vowel schwa?
neutral position (pg.59)
____ is the closed end of the SLVT and _____ is the open end of the SLVT (uniform tube)
glottis; lips (pg.59)
the SLVT can be changed, therefor its is a ______
variable filter (pg.60)
soft tissues of the vocal tract _____ some sound energy
dampen or absorbe (pg.60)
this means the SLVT is a heavily dampened filter
soft tissues allow the SLVT to react to a range of frequencies near peaks of the filter function. this means it is a ______
broadly tuned filter (pg.60)
what formants are the most important for speech perception?
F1, F2, and to a lesser extent F3 (pg.60)
____ have the most open vocal tract shape
vowels (pg.61)
no_____ noise is produced during the articulation of resonant sounds
aperiodic (pg.61)
what is the default sound source?
vocal fold vibration (pg.61)
formant frequencies depend on what?
size of pharynx, oral cavity, and location of constrictions in the SLVT (pg.62)
which formant frequency is most closely associated with pharynx size?
F1 (pg.62)
pharynx size carries with tongue height
the larger the air pocket, the -____ the resonant frequency?
lower (F1 is lower) pg.62
what have the highest tongue position and have a low F1 frequency?
high vowels and glides (pg.62)
the smaller the air pocket, the _____ the resonant frequency is
higher (pg.62)
what have the lowest tongue position and high F1 frequency?
low vowels (pg.62)
which formant frequency is most closely associated with oral cavity size
F2 (pg.62)
oral cavity size varies with tongue advancement
what that the most forward tongue position and have a high F2 frequency
front vowels (pg.62)
what have the farthest-back tongue position and have a low F2?
back vowels (pg.62)
what formant frequency is important for distinguishing the retroflexed vowels (vocalic /r/) and the constant /r/ in english?
F3 (pg.62)
vocal tract constriction for these sounds results in a low F3
as the mouth opens, F2 values tend to move towards the middle of the F2 scale what does this mean for front vowels and back vowels?
front= this means that F2 drops
Back=this means that F2 drops
(pg.62)
For _________ the vocal tract is more constricted than for vowels but less constricted than for obstruent consonants
resonant consonants (pg.63)
resonances from side cavities (for resonant consonants) are absorbed by the side cavity and they do not show up in the output speech signal. what do these appear as?
zeros or anti-resonances (pg.63)
- a zero is the opposite of a formant
- on a spectrogram, a zero will appear as white space
_____ have a complete closure at some locations in the oral cavity
nasal consonants (pg.63)
study the spectrograms in ch. 2
pg.63
what a nasal consonants characterized by?
the presence of zeros in output (pg.64)
_____ have a low frequency formant (often called nasal formant)
nasal consonants (pg.64)
_______ involve a constriction in the vocal tract that does not produce turbulent flow
liquid and glides (pg.64)
True/False: liquid and glides do not produce aperiodic noise
true (pg.64)
acoustically, what do liquids and glides resemble?
vowels (pg.64)
referred to as semivowels
the obstruent sounds of english include…
stops, fricatives and affricates (pg. 65)
for all obstruent sounds, the vocal tract is relatively…
constricted (pg.65)
what is produced when there is turbulent airflow?
aperiodic noise (pg.65)
in ______ airflow through the constriction is continuous
fricatives (pg.65)
characterized by continuant noise
in _____ airflow is completely blocked for brief period of time
stops (pg.66)
characterized by a period of silence during the blockage followed by a burst of engird when the blockage (or closure) is related
what is the period of time from the beginning of the burst till the onset of voicing?
Voiced onset time (VOT) (pg.66)
___ combine the features of stops and fricatives
affricated (pg.66)
airflow is briefly blocked, producing a period of silence, the blockage is then released to a narrow constriction
in a waveform, aperiodic noise is characterized by what?
the lack of a repeating pattern (pg.66)
in english, all obstruents have what?
voiced and voiceless cognates (pg.66)
what serves as a sound source for obstruents?
aperiodic noise (pg.66)
this is why vocal fold vibration is not required to produced an output sound
True/False: for obstruent sounds, voicing is the default sound source?
False: for resonant sounds voicing is the default sound source (pg.66)
_____ obstruents are characterized by shorter durations than _______ obstruents
voiced; voiceless (pg.66)
True/false: as with any sound, air pocket size determines how noise is source is filtered
True (pg.66)
for example:
-when constriction is near the front of the vocal tract, high frequency components of the noise source are enhanced
-when constriction is near the back of the vocal tract, lower-frequency components of the noise source are enhanced
True/false: as the constriction location moves back in the vocal tract, the air pocket in the front of the constriction gets larger
True (pg.66)
what are an important cues to place of articulation for all consonants?
formant transitions (pg.66)
In english, ____ transitions always move downward as you look from vowel toward the consonant
F1 (pg.68)
_____ transitions provide the most information about consonant place of articulation
F2 (pg.68)
for _____ consonants, F2 tends to move downward as the constriction is formed and upward as it is released
bilabial (pg.68)
for ______ consonants, F2 tends to move towards a frequency of about 1800 Hz
alveolar (pg.68)
for ____ consonants, F2 tends to move towards F3
velar (pg.68)
it forms a “velar pitch”
what are the sibilant fricatives?
/s,z, sh, and edge/ (pg.68)
where are the nonsilibant fricatives?
/f,v,th, and h/ (pg.68)
True/False: Sibilant fricatives have higher amplitude than nonsbilant fricatives?
true (pg.68)
most of the noise energy for /s/ is at frequencies above or below 4000 Hz?
above (pg.69)
since the resonating cavity in front of the alveolar ridge is very small
the average frequency of frication noise for /s/ is typically at least 2500Hz higher or lower than for /sh/?
higher (pg.69)
True/false: center of gravity is the average frequency of the spectrum weighted by the amplitude of the noise at different frequencies?
True (pg.69)
what is the degrees to which the energy on either side of the center of gravity is distributed symmetrically or asymmetrically?
skewness or kurtosis?
skewness (pg.69)
kurtosis= the degree to which the noise spectrum is flat or shows clearly defined peaks
in the information provided in spectrum moments, the center of gravity shifts away or towards the center of the spectrum?
away from the center of the spectrum towards the resonant peak (pg.71)
as a result, the spectrum is asymmetrical and energy is concentrated in a relatively compact area rather than being evenly distributed across the spectrum
in stop consonants what provides cues to place of articulation?
voice onset time duration and frequency
or the lack of periodic noise?
VOT (pg.73)
which stops tend to have shorter VOTs then other stops with the same voicing?
bilabial
velar
alveolar
bilabials (pg.73)
which stops tend to have longer VOTs then other stops with the same voicing?
bilabial
velar
alveolar
velar (pg.73)
which stops tend to have either short or long VOTs then other stops with the same voicing?
bilabial
velar
alveolar
alveolar (pg.73)
which stops tend to be flat or falling and have no noticeable peaks?
bilabial
velar
alveolar
bilabial (pg.73)
which stops tend to rise gradually?
bilabial
velar
alveolar
alveolar (pg.73)
which stops tend to have peaks in regions of F1 and F2?
bilabial
velar
alveolar
velar (pg.73)
will disorders speech display a pitch contour?
no, a pitch contour is also known as a waveform. disorders speech will be aperiodic and therefore it can be difficult or impossible to see in disordered voices
(pg.73)
what is cycle-to-cycle variability in frequency?
shimmer or jitter?
Jitter (pg.73)
what is cycle to cycle variability in amplitude?
shimmer or jitter?
shimmer (pg.73)
how do you measure shimmer and jitter?
use a sustained /a/ (pg.76)
_____ is the typical voice quality produced by a healthy speaker and H1 and H2 are approximately equal in amplitude?
modal voice
creaky voice
breathy voice
modal (pg.77)
in _____, the vocal folds pulse irregular and often at a very low frequency and H1 is lower than H2?
modal voice
creaky voice
breathy voice
creaky (pg.77)
in ______, the vocal folds never completely close, resulting in airflow even at maximal closure and H1 is higher in amplitude than H2
modal voice
creaky voice
breathy voice
breathy (pg.77)
True/False: languages do not use voice quality phonemically
False (pg.77)
some languages use voice quality phonemically
______ is a measurement of the amount of periodic versus aperiodic energy in voice
spectral tilt or harmonics-to-noise-ration
harmonics-to-noise-ratio (pg.77)
healthy speakers should be able to produce a harmonics-to-noise-ratio of _____ dB?
20 (pg.77)
this means that speakers should be able to produce about 99% periodic energy
