MNSR 31 - Speech production Flashcards
how is the human voice generated?
generated by a flow of air through the vocal tract.
according to what law how is voice phonation generated?
by bernoulli’s law
if fluid velocity increases - pressure is decreased
function of vocal chords
control openings of trachea
bernoulli equation
P1 + pgh + 1/2pv2^ =constant
how is speech produced via bernoulli
pressure decreases - pressure decrease and velocity increase
a lot of vibration,
how is pressure involved in making sound
The periodic opening and closing (vibration) of the vocal cords creates a pressure wave in air which travels up the vocal tract
(air between vocal chords produced by breathing causes them to move apart - pressure drops and the vocal chords are drawn to each other again - this causes the vibration)
laryngitis
, the vocal cords are swollen due to inflammation or irritation. They are less willing to vibrate, resulting in a hoarse and weak voice
where does vocal tube close and open
closed at the laryngeal end and open at the mouth.
sound from mouth depends on what
depends on the Resonant Properties of the vocal tract.
how does sound travel down a tube
Sound travels down the tube and is strongly reflected if the open end coincides with a wave anti-node.
reflected wave travels back down the tube it interacts with the incident wave and may set up aStanding Wave pattern if the tube length = an integer multiple of the wavelength.
Natural Frequencies of Vibration (NFV) or Resonant Frequencies.
The sound frequencies that set up standing waves within the tube are described as
Lowest NFV
The next integer multiple NFV
The next NFV
Fundamental Frequency (1st Harmonic).
2nd Harmonic Frequency (1st Overtone)
.3rd Harmonic Frequency (2nd overtone), etc.
p(row/density)
mass/volume
the periodic opening and closing of the vocal cords creates a pressure wave. What does this pressure wave consist of?
anti-node = maximal pressure difference node = atmosphere pressure
what is the standing wave
only form if the tube length is an integer multiple of the wavelength.
A reflected wave that interacts with the incident wave
list of overtone and harmonic frequency
overtone - fundamental. 1st, 2nd, 3rd, 4th
harmonic - 1st, 2nd, 3rd, 4th, 5th
resonance frequency
graph of frequency (x axis_ and amplitude (y axis) - the peak of the graph = resonance frequency
what frequencies does NFV frequencies intersect with
NFV frequencies intersect with frequencies that make a node at the closed end of the tube and an anti-node at the open end of the tube
what are the sound frequencies that are allowed to pass through?
sound frequencies that correspond to its resonant frequencies - the rest get filtered out
formant frequencies
the peaks of the frequency spectrum that shows the NFVs of the vocal tract
voice spectrogram
a graph that shows the variation in formant frequencies with time
what causes the variation in formant frequencies
produced by changing the physical dimensions of the vocal tract using the tongue, lips and pharyngeal length
phonated sounds
sounds produced by controlled airflow through vibrating vocal folds e.g. vowels
fricative sounds
sounds created by turbulent air flow within the oral cavity of the lips or through the teeth -e.g. f, k ,ch
