Topic Seven - Speech Production and Spectrographic Analysis

Question 1

What is the source-filter model of speech production?*

Answer 1

The source of speech comes from air being ejected out of the lungs and vibrating the vocal folds.

This speech sources is then filtered through the size and shape of the oral cavity and the position of the tongue.

The changes in the mass and stiffness of the vocal folds result in changes in frequency.

Question 2

How do you define vowels?*

Answer 2

A vowel can be described by its manner and place or articulation and whether it is a long or short sound.

There are also rounded or unrounded vowels which refers to lip position.

Question 3

How do you define dipthongs?*

Answer 3

A diphthong is a type of vowel sound where two vowel sounds are combined in a single syllable, and the tongue glides from one position to another during the articulation.

Question 4

What is a formant and how are they produced?*

Answer 4

A formant is a spectral peak produced by the vocal tract resonances - the position of the vocal articulation.

The frequencies of these resonances is determined by the mass/spring characteristics of vocal tract Helmholtz resonators

There are three formants that are produced, but it is the F1 and F2 that are most important for vowel production

Question 5

What is the difference between monophthongs and diphthongs?*

Answer 5

• There are 12 monophthongal vowels and 8 diphthongal vowels
• In monophthongs, the formant is constant
• In diphthongs, the formant changes

Question 6

See Kahoot on spectrograms, and basic vocal anatomy

Question 7

What is a spectrogram?

Answer 7

3D graphical representations of the frequency content of signals

x-axis = time
y-axis = frequency
colour/shade = intensity

Question 8

How are F1 and F2 determined?

Answer 8

F1
- Based on the tongue being either close to the palate, or open (far from the palate)
- The closer the vowel, the lower the F1

F2
- Where in the mouth is the tongue highest, either front, central or back
- The more front, the higher the F2

Question 9

How do you characterise consonants?

Answer 9

Consonants can be characterised by:

• Voiced/voiceless
• Place of production (alveolar, bilabial, velar, dental)
• Manner (plosive, affricate, fricative, nasal, approximant)

Question 10

How are harmonics, formants and vocal tract resonances depicted on spectrographs?

Answer 10

Harmonics = Series of fine horizontal lines

Formants, vocal tract resonances = wide horizontal bands of increased intensity