Dialogue systems	
Luděk Bártek	
Introduction to Phonetics	
	Luděk Bártek
	Laboratory of search and dialogue, Fakulty of Informatics, Masaryk University, Brno
	spring 2023
	
Introduction to Phonetics
Dialogue systems
Luděk Bártek
Introduction to Phonetics
■ Focuses to different aspects of sound of a language.
■ Speech processing and dialogue systems basic concepts
■ phonemes
■ vowels - form ants
■ consonants - voiced/unvoiced consonants
■ co-articulation
■ form of sonority
	Phonemes and Phonetic Transcription
Dialogue	
systems	
Luděk Bártek	■ Phoneme - elementary sound segment, corresponding to
Introduction to Phonetics	character units of the language system (morphemes).
	■ Phonetic transcription - written text transcription into the
	corresponding phonetic form:
	na shledanou —>> na zhledanou   na schledanou
	■ Phonetic alphabet - used to unambiguous phonetic
	transcription
	■ International Phonetic Alphabet (IPA) - part of the
	UNICODE standard
	■ (Speech Assessment Methods Phonetic Alphabet -
	SAM PA) - 7 bit IPA transcription used by automatic
	speech processing (MBrola TTS for example).
	
Czech Phonetic Transcriptions Examples
Dialogue systems
Luděk Bártek
Introduction to Phonetics
■ Phonetic transcription of sentence: „Ukázka fonetických transkripcí"
■ IPA: 'uka:ska f'onet,itski:x tr'anskriptsi:
■ SAMPA: ukAska foneticklH transkripcsl
Vowels
Czech
Dialogue systems
Luděk Bártek
Vowel - forms a syllable. Czech vowels classification:
■ short: a, e, i, o, u
■ long: a, e, i, 6, u
■ diphthongs: eu, au, ou
Contains:
■ Fq- a vocal cords vibration frequency (approx, 100 — 400 Hz)
■ formants - frequencies formed by resonance of sound in the cavities of the a voice tract.
□ e
	Form ants
Dialogue	
systems	
Luděk Bártek	■ Frequencies created and amplified by resonance in cavities
Introduction	of the vocal tract.
to Phonetics	■ Fi - resonance in oral cavity.
	
	■ F2 - resonance in laryngeal cavity.
	■ There are even higher formants (F3, ...) - existence is
	individual.
	■ Formants presence and intensity depends on:
	■ sex - male/female
	■ age - childhood/adolescence/adult/senior age
	■ health - cold, hoarseness, larynx and vocal cords diseases, ■ ...
	
Czech Vowels F\ and F2 Formats
Dialogue systems
Luděk Bártek
Introduction to Phonetics
Vowel	Fi		F2	
a	700 -	- 1100 Hz	1100 -	- 1500 Hz
e	500-	- 700 Hz	1500 -	- 2000 Hz
■ 1	300-	- 500 Hz	2000 -	- 3000 Hz
0	500-	- 700 Hz	900-	- 1200 Hz
u	300-	- 500 Hz	600-	- 1000 Hz
Tabulka: Vowels F\ and F2 formants
Czech Vowels Frequency
Dialogue systems
Luděk Bártek
Introduction to Phonetics
Vowel (s)	Relative frequency
[e]	10 %
[a], [o], [i]	6 — 7 %
F]	4%
[á], [u], [é], [ou], [ú]	<4%
[6], [au], [eu]	uncommonly
Consonants
Dialogue systems
Luděk Bártek
Consonants, opposite to vowels, are dynamic actions.
Strongly dependent on a context of their occurrence.
Only parts of some consonants have a tonal character. Divided according to:
■ voiced - created in larynx, contains basic vocal tone.
■ unvoiced - created in voice tract cavities (nasopharyngeal, oral, ...), can be a noises (sibilants, for example):
■ Problematic start of the speech detection in noisy sound source/environment.
■ Voiced and unvoiced consonants can be in pairs (pair consonants) for example:
■ r/l
■ b/p
■ d/t