Download Vocal Tract Musculature

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts
no text concepts found
Transcript
Vocal Tract Physiology
April 5, 2013
The Toolkit
•
There are four primary active articulators in speech.
•
(articulators we can move around )
1. The lips
2. The lower jaw (mandible)
3. The tongue
4. The velum
•
The pharynx can also be constricted, to some extent.
•
Separate sets of muscles control each articulator...
Articulatory Speed
• The gold medal goes to the tongue tip...
• which is capable of 7.2 - 9.6 movements per
second.
• The rest:
• Mandible
5.9 - 8.4 movements per second
• Back of tongue 5.4 - 8.9
• Velum
5.2 - 7.8
• Lips
5.7 - 7.7
• Note: lips can be raised and lowered faster than they
can be protruded and rounded.
1. The Lips
• The orbicularis oris
muscle surrounds the lips.
• Contraction compresses
and rounds the lips.
• A muscle called the
mentalis also protrudes
the lips.
• Contraction of the
risorius muscle retracts
the corners of the lips...
• and spreads them.
By the way...
• The vowel [i] is typically produced with active lip
spreading.
• “Say cheese!”
• What acoustic effect would this have?
• Lips Normal:
• Lips Spread:
• Check ‘em out in Praat.
2. The Jaw
• Several different muscles are used to both lower and
raise the mandible.
• Primary raisers:
• Masseter
• Temporalis
• Internal
pterygoid
2. The Jaw
• Several different muscles are used to both lower and
raise the mandible.
• Lowerers:
• Anterior belly
digastricus
• Geniohyoid
• Mylohyoid
• Note: in lowering, the mandible also retracts.
Articulatory Control
• People can produce vowels perfectly fine even when
a bite block holds their jaws open. (Lindblom, 1979)
• Adults get the formants right, right from the start...
• But kids need a little time to adjust.
• Abbs et al. (1984) experimented with pulling down
people’s jaws...
• when they had to say sequences like [aba] and
[afa]!
Abbs et al. EMG data
• Lip muscles
adjust
immediately for
the sudden jaw
lowering...
• Adjustment
happens faster
than electrical
signals can
travel to the
motor cortex
and back!
3. The Tongue
•
The muscles controlling the tongue consist of:
1. Intrinsic muscles
•
(completely within the tongue)
2. Extrinsic muscles
•
•
(connect the tongue to outside structures)
The intrinsic muscles include:
1. The superior longitudinal muscle
2. The inferior longitudinal muscle
3. Transverse muscles
4. Vertical muscles
Tongue: Sagittal View
• The superior
longitudinal muscle
pulls the tongue tip up
and back.
• Instrumental in
producing alveolars
and retroflexes.
• The inferior
longitudinal muscle
pulls the tongue tip
down and back.
• Helps with tongue
blade articulations.
Tongue: Coronal View
• The transverse muscles pulls in the edges of the
tongue, and also lengthens the tongue to some extent.
• Helpful in producing laterals.
• Contraction of the vertical muscles flattens the tongue.
• Interdentals?
Extrinsic #1: Genioglossus
• The genioglossus
connects the tongue to
both the mandible and the
hyoid.
• Contraction of the
posterior genioglossus
moves the whole tongue
up and forwards.
• Crucial in palatals.
• Contraction of the
anterior genioglossus
curls the tongue tip down
and back.
Gene-ioglossus
Gene Simmons, of the rock band KISS, is
famous for his use of the genioglossus muscle.
Extrinsic #2: Styloglossus
• The styloglossus
connects the tongue to the
“styloid process” in front of
the ear.
• Pulls the tongue up and
back.
• ...for velar articulations.
• May also help groove
(sulcalize) the tongue.
Extrinsic #3: Hyoglossus
• The hyoglossus
connects the tongue to the
hyoid bone.
• Pulls the tongue down
and back.
• = pharyngeals
• Can also pull the sides of
the tongue down.
Extrinsic #4: Palatoglossus
• The palatoglossus connects
the tongue to the soft palate.
• Can be used to raise the back
of the tongue.
• And also to lower the
velum!
• Lowering the back of the
tongue may inadvertently pull
the velum down...
• leading to passive
nasalization of low vowels.
• Note: Great Lakes vowel shift
Chain Shifting
• The Great Lakes Shift is called a chain shift, because
first one vowel moves...
• And then a series of others follow.
• In this case, the first shift was:
• Theory: vowels have to stay distinct from one another.
• So listeners can understand what’s being said.
Back to the Shift
• The Great Lakes Shift was first noticed in the 1960s.
The Shift, Diagrammed
4. Velar Muscles
• The levator palatini
raises the velum.
• (connects the velum to
the temporal bone)
• The velum is lowered by
both the palatoglossus and
the palatopharyngeus...
• which connects the
palate to the pharynx.