Topic 8: Foundation of speech processing Flashcards
Speech Production
sound produced by pushing air out of the lungs
when exhaled, pass through trachea and larynx where it can be influences by the vibration of the vocal cords..also called vocal folds..gap between vocal folds is called glottis
the air then passes through pharyngeal cavity (throat) and finally to oral or nasal cavity
after that depends on articulators: velum, tongue, lips, and jaw
vocal tract is the connected passages that starts from larynx and include pharynx, oral cavity and nasal cavity
Larynx model
memorize this
Speech production diagram
soft palate hard palate nasal cavity nostril lip tongue pharyngeal cavity larynx
Human articulator
described the principle parts of
- upper surface of vocal tract
- lower surface of vocal tract
aveolar ridge
small protuberance that you can feel with the tip of the tongue when
you slide it from the upper teeth backwards
hard palate
the front part of the roof of the mouth formed by a bony structure
soft palate
located further back at the back of the mouth, a muscular flap
that can be raised to press against the back wall of the pharynx and to form “velic closure”
which prevents the air escaping through the nose when producing nasal sounds
uvula
small appendage hanging down at the lower end of soft palate
pharynx
part of vocal tract between uvula and larynx
larynx
houses vocal cord
Tongue label
blade front of tongue center of tongue back of tongue root epiglottis
recap speech production
components required
- airstream mechanism
- state of vocal cords
- velum position
- place of articulation
- manner of articulation
airstream mechanism
provide source of energy to generate speech sounds using airflow and pressure in the vocal tract
there are 4 types based on where the airflow is initiated and the direction
- in the lungs
- at velum
- at glottis (outward) breath out
- at glottis (inward) breath in
state of vocal cords
the state distinguish between voiced and voiceless
voiceless - vocal cord held wide apart, air passes directly through the glottis
voiced - vocal cord brought close together but not tightly closed. air passing between cords causing vibration of the cords
- vibration are far too fast to be seen with naked eye
- vibration average 130/s for male, 230/s for female
- longer and larger cords produce slower vibration
- all vowels are voiced
Velum position
allows us to distinguish between nasal or oral sounds
oral sound produced when velum is raised so that there is a velic closure and air prevented from escaping through nose.
nasal sound is when velum is lowered. air goes through the nose.
Place of articulation
consontant is formed due to the airstream obstruction in the vocal tract.
Consonants are classified depending on the place and manner of this
obstruction known as place and manner of articulation.
Place of articulations refers to the horizontal relationship between the
articulators
lips - labial
tongue tip and blade - coronal
back of tongue - dorsal
labial: labial
formed by upper and lower lip
eg /b/ /p/ /m/
labial: labiodental
/f/ pronounced using upper teeth and lower lip
coronal: dental
tongue placed against teeth
thigh, father
coronal: post-dental
produced using tip of tongue and upper teeth and area just behind them
aveolar
place of articulation is aveolar ridge and tip of tounge is active articulator
eg /r/ /s/ /z/
post-aveolar
place of articulation is front of hard palate and blade of tounge is the active articulator
eg, shrew measure
palato-aveolar
place of articulation is down behind the lower front teeth or at the back of the aveolar ridge..blade is always placed close to the back part of aveolar ridge
eg sigh, sea, sew
palatal
the place of articulation is at the hard palate and the front of the
tongue is the active articulator
yacht, yawn
Retroflex:
the place of articulation is at the back of the alveolar ridge and
the tip of the tongue is the active articulator.
not used in english speech
dorsal: velar
the place of articulation is at velum (soft palate) and back of the
tongue is the active articulator
eg
hack hag hang
dorsal: uvular
are formed by the back of the tongue and uvula. Not use in
English
pharyngeal
tongue root and pharynx wall
glottal
vocal cords are the active and passive articulator
Manner of articulation
oral sounds nasal sounds stops fricatives affricatives liquids glides approximant aspiration
vowel articulation
articulated with an open
approximation i.e. the articulators are
positioned relatively wide apart so that the
airstream flows unobstructed through the oral
cavity
important features of vowels
- horizontal and vertical position of tongue
- degree of lip rounding
Consonants and Vowels
consonant is a speech sound that is
articulated with complete or partial closure of the vocal tract
Vowel is the speech sound that is produced without any obstruction
on the vocal tract
Consonant: Plosive
Plosive: a momentary blockage of the vocal tract, which can optionally followed by a release burst
Example of plosives are: /p/, /b/, /t/, /d/, /k/, /g/
Duration of the blockage usually between 50-100 ms
Consonant: Fricative
Fricative: a narrow constriction maintained somewhere in the vocal
tract. When air passes through the constriction noise is resulted
Fricative can be classified as voiced and voiceless
Consonants: Nasal
the nasal consonants are produced with closure of the oral cavity
and radiation of the sound through the nasal cavity
FEATURES OF VOWELS
Monophthongs
Diphthongs
Tense and lax vowels
nasal vowels
IPA chart
remember the vowels
Transcription
method that employs a standard spelling system using existing symbols of each target language
orthographic transcription
phonemic transcription
phonetic transcription
Phonemic vs Phonetic transcription
Phonemic transcription
• The representation of the phonemes to which allophones belong
• Symbols are enclosed in square brackets [ ]
• Phonemic transcription is a type of broad transcription, that is, a transcription that
shows an absence of phonetic detail
• The value of symbols (phonemic alphabet) used in phonemic transcription is
idiosyncratic and differs from language to language
Phonetic transcription
• The representation of predictable variants of allophones
• Symbols are enclosed in double slash / /
• Phonetic transcription is a type of narrow transcription, that is, a transcription
which contains a certain amount of phonetic detail
• The phonetic alphabet is universal
studies of speech sounds: phonetics and phonology
phonetics is a study of production, transmission and reception of speech sounds.
- articulary phonetics
- auditory phonetics
- acoustic phonetics
phonology is a study of how sounds are organized and used in natural language
phonological system of a language includes inventory of sounds, the features and rules specifying how sounds interact with each other
can be divided into
- segmental phonology
- suprasegmental phonology
Phoneme
smallest unit of speech that distinguish meaning
give example
- not universal but specific to language
- divided into consonants and vowels
- abstract units
Allophones
predictable phonetic variants of a phoneme. actual pronounciation of those abstract units in different context.
