MNSR 31 - Speech production

Question 1

how is the human voice generated?

Answer 1

generated by a flow of air through the vocal tract.

Question 2

according to what law how is voice phonation generated?

Answer 2

by bernoulli’s law

if fluid velocity increases - pressure is decreased

Question 3

function of vocal chords

Answer 3

control openings of trachea

Question 4

bernoulli equation

Answer 4

P1 + pgh + 1/2pv2^ =constant

Question 5

how is speech produced via bernoulli

Answer 5

pressure decreases - pressure decrease and velocity increase
a lot of vibration,

Question 6

how is pressure involved in making sound

Answer 6

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)

Question 7

laryngitis

Answer 7

, the vocal cords are swollen due to inflammation or irritation. They are less willing to vibrate, resulting in a hoarse and weak voice

Question 8

where does vocal tube close and open

Answer 8

closed at the laryngeal end and open at the mouth.

Question 9

sound from mouth depends on what

Answer 9

depends on the Resonant Properties of the vocal tract.

Question 10

how does sound travel down a tube

Answer 10

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.

Question 11

Natural Frequencies of Vibration (NFV) or Resonant Frequencies.

Answer 11

The sound frequencies that set up standing waves within the tube are described as

Question 12

Lowest NFV
The next integer multiple NFV
The next NFV

Answer 12

Fundamental Frequency (1st Harmonic).
2nd Harmonic Frequency (1st Overtone)
.3rd Harmonic Frequency (2nd overtone), etc.

Question 13

p(row/density)

Answer 13

mass/volume

Question 14

the periodic opening and closing of the vocal cords creates a pressure wave. What does this pressure wave consist of?

Answer 14

anti-node = maximal pressure difference
node = atmosphere pressure

Question 15

what is the standing wave

Answer 15

only form if the tube length is an integer multiple of the wavelength.
A reflected wave that interacts with the incident wave

Question 16

list of overtone and harmonic frequency

Answer 16

overtone - fundamental. 1st, 2nd, 3rd, 4th

harmonic - 1st, 2nd, 3rd, 4th, 5th

Question 17

resonance frequency

Answer 17

graph of frequency (x axis_ and amplitude (y axis) - the peak of the graph = resonance frequency

Question 18

what frequencies does NFV frequencies intersect with

Answer 18

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

Question 19

what are the sound frequencies that are allowed to pass through?

Answer 19

sound frequencies that correspond to its resonant frequencies - the rest get filtered out

Question 20

formant frequencies

Answer 20

the peaks of the frequency spectrum that shows the NFVs of the vocal tract

Question 21

voice spectrogram

Answer 21

a graph that shows the variation in formant frequencies with time

Question 22

what causes the variation in formant frequencies

Answer 22

produced by changing the physical dimensions of the vocal tract using the tongue, lips and pharyngeal length

Question 23

phonated sounds

Answer 23

sounds produced by controlled airflow through vibrating vocal folds e.g. vowels

Question 24

fricative sounds

Answer 24

sounds created by turbulent air flow within the oral cavity of the lips or through the teeth -e.g. f, k ,ch