Speech disorders refer to problems producing speech sounds or voice quality. This document classifies and describes different types of speech disorders: - Speech sound disorders involve incorrect or unclear production of phonemes. These include articulation disorders from motor issues and phonological disorders from linguistic issues. - Fluency disorders affect speech rhythm and include stuttering and cluttering. - Voice disorders involve abnormal vocal quality, pitch, loudness or duration. These can be organic from physical issues or functional when structures are normal. - Prevalence data is provided for speech disorders in the US, UK and Pakistan, with millions affected in each region.

1. Classification
of
Speech
Disorders
Dr. Shazia Tahira
(Audiology & Speech-Language Pathology)

2. Speech & Speech Disorders
Speech refers specifically to sounds
produced by the oral mechanism,
including the lips, tongue, vocal cords,
and related structures.
Speech Disorders refer to problems in
producing the sounds of speech or
with the quality of voice.
People with speech disorders may:
 not say sounds clearly
 have a hoarse or raspy voice
 repeat sounds or pause when
speaking

3. Language Disorders Are Distinct From Speech Disorders
Language refers to the code, or a
system of words and symbols—written,
spoken or expressed with gestures and
body language—that is used to
communicate meaning and for
transforming unobservable mental
events, such as thoughts and
memories, into events that can be
perceived by other people.
Language Disorders are an impairment
of either understanding linguistic
information (Receptive Language) or
the ability to use and share linguistic
information (Expressive Language) and
are not related with speech production.

4. Classification of Speech Disorders
Speech
Sound
Disorders
Fluency
Disorders
Voice
Disorders

5. Speech Sound Disorders
A Speech Sound Disorder (SSD) is a speech disorder in which some speech sounds
(called phonemes) are either not produced, not produced correctly, or are not used
correctly.
Speech sound disorders can be organic or functional in nature.
 Organic Speech Sound Disorders result from an underlying motor/neurological,
structural, or sensory/perceptual cause.
 Functional Speech Sound Disorders are idiopathic—they have no known cause.

6. Organic and Functional Speech Sound Disorders
Organic Speech Sound Disorders
include those resulting from
 Motor/Neurological
Disorders (e.g., childhood apraxia
of speech and dysarthria)
 Structural
Abnormalities(e.g., cleft
lip/palate and other structural
deficits or anomalies)
 Sensory/Perceptual
Disorders (e.g., hearing
impairment).
Functional Speech Sound Disorders
include those related to the
 Motor Production of Speech
Sounds (articulation disorders or
phonetic disorders)
 Linguistic Aspects of Speech
Production (phonological disorders
or phonemic disorders)

8. Articulation Disorders and Phonological Disorders
 Articulation disorders (Phonetic
Disorders) focus on errors (e.g.,
omissions, substitutions, and
distortions) in production of individual
speech sounds.
 Omissions:(bo for boat)
 Substitutions: (wabbit for rabbit)
 Distortions: (shlip for sip)
 Phonological Disorders (Phonemic
Disorders) focus on predictable, rule-
based errors (e.g., fronting, stopping,
and final consonant deletion) that
affect more than one sound.
Phonological disorders are considered both
speech and language disorders because it is the
language system that is affected but they
are also a speech sound disorders in that the
errors relate to use of phonemes (speech
sounds). This makes it different from specific
language impairment, which are primarily
disorders of the morphology (word structure),
syntax (grammar), semantics (meaning)
and pragmatics (usage) of language rather than
the sound system.
It is often difficult to clearly
differentiate between articulation
and phonological disorders; therefore, many
researchers and clinicians prefer to use
the broader term "speech sound disorder" when
referring to speech errors of unknown cause.

9. Articulation Disorder (A Speech Sound Disorder)
“Be vewwy vewwy quiet…I’m
hunting wabbits.”

10. Apraxia of Speech and Dysarthria
 Apraxia of Speech (AOS) or Acquired Apraxia of Speech is an
acquired oral motor speech disorder affecting an individual's ability to translate
conscious speech plans into motor plans, which results in limited and difficult
speech ability. AOS affects willful or purposeful movement patterns and usually
also affects automatic speech. Apraxia of speech can be caused by impairment to parts
of the brain that control muscle movement and speech. Individuals with AOS have
difficulty connecting speech messages from the brain to the mouth. AOS is a loss of
prior speech ability resulting from a brain injury such as a stroke, trauma, progressive
illness or tumor. AOS can affect a person at any age although it mostly typically occurs
in adults.
 Childhood Apraxia of Speech (CAS) is an inability to utilize motor planning to perform
movements necessary for speech during a child's language learning process. The cause
may be genetics and sometimes there is no observable cause. Although the causes may
differ between AOS and CAS, the main characteristics and treatments are similar.
 Dysarthria is a motor speech disorder characterized by difficulty articulating sounds.
The difficulty in articulation does not occur in planning the motor movement, as
happens with Apraxia of Speech. Instead, dysarthria is caused by inability in or
weakness of the muscles in the mouth, face, and respiratory system. Dysarthria can
result from congenital conditions, or it can be acquired at any age as the result of
neurological injury, disease, or disorder.

11. The muscles involved in
speech need to move in
a coordinated manner in
order to produce Speech
Sounds.
These movements are
controlled by brain and
are also dependent upon
speech muscles strength
In Apraxia, the speech muscles are
normal and of normal strength but
the brain signals that control
movements of these muscles during
speech become abnormal
In Dysarthria, the brain signals that
control movement of speech
muscles during speech are normal
but speech muscles are weak and
not able to move

12. Fluency Disorders
Fluency is the aspect of speech production that refers to continuity, smoothness,
rate, and effort.
Fluency disorders are difficulties with the rhythm and timing of speech
characterized by hesitations, repetitions, or prolongations of sounds, syllables,
words, or phrases. Common fluency disorders include:
 Stuttering: rapid-fire repetitions of consonant or vowel sounds especially at
the beginning of words, prolongations, hesitations, interjections, and
complete verbal blocks
 Cluttering: excessively fast and jerky speech

13. Stuttering (A Fluency Disorder)
“I w-w-w-
want a job.”

14. Voice Disorders
Voice disorders are problems with the quality or use of
one's voice resulting from disorders in the larynx.
Voice disorders are characterized by abnormal
production and/or absences of vocal quality, pitch, loudness,
resonance, and/or duration.
Voice Disorders are classified as:
 Organic — voice disorders that are physiological in nature
 Functional — voice disorders when the physical structure is
normal

15. Organic and Functional Voice Disorders
Organic voice disorders are physiological in nature
and result from alterations in respiratory, laryngeal, or
vocal tract mechanisms
 Structural — organic voice disorders that
result from physical changes
in the voice mechanism (e.g., alterations in
vocal fold tissues such as edema
or vocal nodules; structural changes in
the larynx due to aging)
 Neurogenic — organic voice disorders that
result from problems with
the central or peripheral nervous system
innervation to the larynx that
affect functioning of the vocal mechanism
(e.g., vocal tremor, spasmodic dysphonia, or
paralysis of vocal folds)
Functional voice disorders result from
improper or inefficient
use of the vocal mechanism when the
physical structure is normal
(e.g., vocal fatigue;
muscle tension dysphonia or
aphonia; diplophonia; ventricular
phonation)

16. Prevalence of Speech Disorders in USA
According to NIDCD (National Institute of
Deafness and other Communication Disorders)
 Nearly 1 in 12 (7.7 percent) U.S. children
ages 3-17 has had a disorder related to
voice, speech, language, or swallowing in the
past 12 months
 5 percent of U.S. children ages 3-17 have a
speech disorder that lasted for a week or
longer during the past 12 months.

17.  The prevalence of speech sound disorders (namely, articulation disorders
or phonological disorders) in young children is 8 to 9 percent. By the first grade, roughly
5 percent of children have noticeable speech disorders, including stuttering, speech
sound disorders, and dysarthria; the majority of these speech disorders have no
known cause.
 More than three million Americans (about one percent) stutter. Stuttering
can affect individuals of all ages, but occurs most frequently in young children between
the ages of 2 and 6. Boys are two to three times more likely than girls to stutter.
Although most children who stutter outgrow the condition while young, as many as one
in four will continue to stutter for the rest of their lives, a condition known as
persistent developmental stuttering.
 An estimated 17.9 million U.S. adults ages 18 or older, or 7.6%, report having had a
problem with their voice in the past 12 months. Approximately 9.4 million (4.0%) adults
report having a problem using their voice that lasted one week or longer during the last
12 months.
 1.4 percent of U.S. children have a voice disorder that lasted for a week or longer
during the past 12 months.

18. Prevalence of Speech Disorders in UK
According to a research by Geoff Lindsay and Steve Strand:
 Speech, language, and communication needs comprised
the third most prevalent type of Special Educational
Needs (SEN) with 15.7% of those with SEN having Speech,
Language, and Communication Needs (SLCN) as
their primary SEN at School Action Plus or above special
educational needs support.
 Only students with moderate learning difficulties (MLD:
24.3%) and behavioral, emotional, and social difficulties
(BESD: 23.7%) were more prevalent than speech, language
and communication needs (15.7%) in special
educational needs support.
According to Talking Point UK, over one million children in
the UK have some kind of speech language and
communication needs.

19. Prevalence of Speech
Disorders in Pakistan
A survey conducted in Karachi to gauge the number of
those affected elaborated the picture. It concluded that
an estimated over 2.2 million individuals in an overall
population of over 16 million suffered from speech,
language, swallowing and/or hearing disorders.
According to Amina Siddiqui, Principle, Ziauddin College
of Speech Language and Hearing Sciences, 14 percent of
total population in Pakistan is affected by speech and
language disorder.

20. For Giving Your Time