Speech and language therapy is recommended for anybody who has problems with their speech and/ or communication, perhaps due to a developmental or neurological disorder. Conditions which usually affect speech include developmental disorders like autism which can cause problems with social skills and the use of additional communicative techniques such as facial expressions and body language, leading to a lack of the ability to communicate their desires with others.
Medical conditions such as strokes and cancers, particularly of the mouth and throat, can also lead to speech and language disorders, as can accidents which injure the brain and articulators. Speech and language therapy can also help those with swallowing and hearing difficulties.
Other related occupations to this field include nurses, who assist with the diagnosis and treatment of patients mainly in hospitals. Furthermore, speech and language therapists work alongside teachers to provide training on how to treat and implement therapy towards aiding students’ speech and language impairments. These teachers help to educate students and alter teaching styles to suit the needs of those with disabilities, in order to enable them to learn the curriculum and life -skills such as how to socialise with others, in a way that is efficient for them. Psychologists also help to implement therapy for those who have depression, anxiety and other psychological illnesses and disturbances relating to social, emotional and physical human behaviours which may arise due to conditions which are also linked to speech and language disorders. Physical therapists help to remedy physical disabilities and use physiotherapy to improve motor skills such as speech, writing, walking and ease physical pain and tension. Physical disabilities or injuries are a result of a spectrum of disorders ranging from sporting injuries to strokes. Occupational therapists also assist patients who are suffering from similar aforementioned disorders or who have suffered serious health problems such as strokes, with returning to work and being able to recover functional skills in their independent everyday lives, for example from being able to wash themselves again.
The Thyroid Cartilage is one cartilage which forms the Larynx and contains two plates, or laminae, which meet at a raised ‘notch’ known as the ‘Adam’s Apple’ and is more prominent in males. The cartilage consists of two superior horns and two inferior horns, an oblique line which connects the sternothyroid, thyrohyoid, and muscles and the median cricothyroid ligament attaching the cricoid to the thyroid cartilage. The Thyroid Cartilage is important in speech production as it contains and protects the vocal folds.
The Pharynx is part of the Respiratory Tract and acts as a passageway for respiratory and digestive functions. Thus, air traveling to the larynx and the lungs from the nasal cavity and bolus traveling from the oral cavity to the oesophagus pass through the pharynx, which is situated behind the oral and nasal cavities.
The pharynx is composed of three parts, firstly the nasopharynx which connects the nasal cavity and the soft palate, then the oropharynx which contains the tonsils, tongue, pharyngeal walls and soft palate and finally the laryngopharynx which is positioned between the hyoid bone and the larynx and oesophagus and separates food and air.
The Trachea is positioned under the larynx and extends to behind the sternum of the chest with a length of approximately 4 inches and a diameter of 1 inch on average. It is formed of between 16-20 incomplete rings of cartilage which are connected together by ligaments. The rings of the trachea have no cartilage at the posterior wall to enable their attachment to the Esophageal muscle. The trachea is formed of two parts. Firstly, there is the Cervical portion with is situated in the neck and the Thoracic portion which is in the thorax.
The Bronchi are an extension of the Trachea which act as airways to the lungs. They are stable and durable as they are formed of cartilage. Bronchi allow for efficient gas exchange and transport oxygen to the lungs whilst also filtering carbon dioxide away from them. The bronchi include the main bronchi which separate into lobar bronchi. There are three lobar bronchi for the right lung and two for the left. The lobar bronchi then separate into segmental bronchi, with ten for the right lung and nine for the left. Finally, the bronchi branch out into many smaller bronchioles which have a diameter of only 0.5mm, known as terminal bronchioles.
The lungs are a vital organ essential for respiration as they absorb oxygen and expel carbon dioxide. This organ is contained within the thorax and is protected by the rib cage. The lungs are elastic and expand upon inhalation to allow for an increased volume of air as the diaphragm contracts and moves downwards. The lungs contract during exhalation as air is released via the nasal and oral cavities. They are essential in speech because air is brought from the lungs to the larynx during respiration, which is manipulated by the vocal folds abd articulators.
A ligament is connective tissue which is fibrous and has the purpose of connecting bones within the body. Membrane, however, is found on the outside of a cell and is a permeable thin layer. The Thyrohyoid membrane is extrinsic, meaning that it connects other structures outside of the larynx to it. Specifically, it connects the hyoid bone and the thyrohyoid cartilage together. This membrane also forms ligaments called thyrohyoid ligaments which connect the hyoid bone to the superior horn of the thyroid. This superior horn is an upward-pointing addition of the Thyrohyoid membrane. There are also Inferior horns which are downward-pointing. The Hypoepiglottic ligament connects the hyoid bone to the epiglottis. The Crichotracheal membrane connects the first ring of the trachea to the cricoid cartilage. The intrinsic ligaments and membranes are small structures binding the laryngeal cartilages together and allow them to be supported. The Quadrangular membrane is the superior portion of the intrinsic ligaments and membranes, is thick and combines with the mucosa folds to form the vocal cords. The crychothyroid membrane is attached to the cricoid cartilage, the thyroid cartilage and artyenoid cartilage and also forms the vocal cords. The conus elasticus is the elastic lateral part of the cricothyroid membrane. Thus, the ligaments and membranes function as a group to hold the vocal organs and bone structures together in order to function as one system.
The human vocal tract filters sounds and distinguishes them into the vowels and consonants of speech and is thus essential in allowing for the function and delivery of the human communication system of speech and language. The vocal tract is comprised of the pharyngeal, nasal and oral cavities. The pharyngeal cavity acts as a passageway for bolus and air necessary in the operation of the digestive and respiratory systems. The nasal cavity is inside the nose and is essential for respiration and scent during digestion and maintains the moistness of the nose and filters air. The oral cavity contains many surrounding nerves and muscles which manipulate the articulator organs in order to produce specific speech sounds.
These articulator organs include the teeth, lips, cheeks, jaw, tongue, hard and soft palates and pharynx which operate together to produce arbitrary speech sounds from acoustic energy. The lungs are essential in this system for allowing a source of energy and the vocal cords are essential in creating a variety of pitches and sounds. The larynx acts as a passageway for the energy, or air. Ultimately, air is forced through the articulators in certain ways in order to produce specific sounds. For example, pressing the lips together creates the bilabial, consonant sound /b/.
The vocal folds lie tightly across the top of the trachea, form the larynx and are inside the thyroid cartilage. The false vocal folds adduct together over the opening of the larynx to prevent bolus from entering. The true vocal cords help produce the sounds used in human speech as they vibrate when air passes through, called ‘voicing’. These manipulated movements alter the pitch and frequency of speech sounds and thus each individual person’s tone or pitch of voice.
The true vocal folds are formed of 5 different layers. The most medial layer is the Thyroarytenoid muscle, which is thick and forms the main mass of the vocal fold. Inner to this muscle, is the Deep Layer, which has lower elasticity and is formed of collagen, or protein, and is fibrous. The Intermediate layer is also fibrous but has more of an elastic or rubbery consistency. Combined, these are referred to as ‘transition’ as they lie between the inner and outer-most layers which differ greatly in texture. Then, is the Superficial Layer, or Reinke’s space, which is viscous with a gel-like texture due to its loose cell structure and thus is able to move easily during air pressure, producing necessary vibrations to create sound. The lateral layer is called the Epithelium, forming the surface of the larynx and acting as a support for the vocal fold shape. Combined, these two layers are referred to as the ‘cover’ of the vocal fold.
Acoustic phonetics is the study of the sound waves of speech once it has been articulated.
Sound waves are what allow sound, such as speech, to travel to the eardrum of the hearer to then be processed psychologically to decipher meaning. They are vibrations which cause a reaction to travel through the air and other materials.
The frequency of a sound is the number of waves which pass per second and this can be measured in Hertz. For example, if a sound wave has a measurement of 80 Hertz, this means that 80 waves have passed each second. The frequency of a sound corresponds to its pitch, or how high or low it is. The lower the frequency of a sound is, then the lower the pitch. The intensity of a sound is known as the amplitude and is measured in decibels (db). A sound’s intensity is its perceived volume. This measurement is not independent. It is both a sound’s amplitude and frequency which correspond to its volume as a matter of how much overall energy is produced with the sound. Furthermore, when a sound’s intensity is measured, it is measured in relation to another sound. For example, whispering nearby to someone is 20 decibels more (30 Db) than normal breathing (10 db).
Furthermore, every object vibrates naturally and the rate at which it does so, is known as the object’s resonance. This is dependent on its physical qualities, such as shape, size and material. An object will vibrate the most and therefore release most sound waves when it experiences additional vibrations at a frequency at an equal level to its resonant frequency. For example, a weak bridge might have a resonant frequency equal to gusts of wind produced by a storm and thus an equal resonance to that bridge would damage and collapse it as the energy and vibrations produced would be most powerful.
The stages in children’s first language acquisition describe how and when children should be learning to develop the ability to understand and produce speech. The first stage of child language acquisition is the ‘Pre-Talking’ stage at 0-6 months old. The baby is able to respond to sounds shown through turning of their head towards the speaker, for example. Vowel- like sounds are produced to express emotions but not consonant sounds.
The second stage is the ‘Babbling’ stage between 6-8 months with some combinations of vowels and consonants produced. The holophrastic stage between the ages of 9 to 18 months shows the child producing a single word used to portray a complete meaning such as emotions or desires towards people and objects.
The Two- word stage occurs from 18-24 months. The child can now produce and intonate two consecutive words. Consonants are beginning to be produced. The Telegraphic stage happens between ages 24 and 30 months. The child can produce simple sentences with syntactic rules but without function words.
Finally, the Later Multiword Stage occurs at the age of 30 months onwards where children rapidly learn the vocabulary of their native language and understanding of speech is proficient. The age of five is known as the ‘critical period’ of language acquisition whereby if a child is older than this when they begin to learn a language it is more difficult.
Bilingualism is when there is knowledge of more than just one native. Bilingual children are thought to have a greater range of vocabulary, working knowledge of languages and be able to consider when to use one language or the other. Thus, they are thought to be more open-minded and flexible particularly as they also have a higher awareness and empathy towards different language structures and cultures. Bilingual children are able to change from the linguistic rules and vocabulary of one language to, so are suggested to be better at multitasking, re-directing and prolonging their attention. Some structures of one language can be similar to that of the other and therefore knowing two languages may mean that each one is reinforced.
Overall, it is suggested that bilingualism leads to healthier brain capacity and function due to the constant activation of particular brain networks.
Behavioural Observation Audiometry is used to test the speech perception of a patient under 6 months old, observes a patient’s responses and behaviour towards sounds and is carried out over a series of sessions. The parent holds the patient inside the testing booth, opposite the test assistant whose role is to confirm any displayed responses from the patient with the audiologist to increase test accuracy. The audiologist chooses sounds known as Narrow Band Noise or Warble tones which have frequencies ranging from 250 to 8000 Hz. A loudspeaker or earphones can be used to play the sounds. Measured responses from the patient include physical responses such as a turn of the head, but ultimately it is difficult to measure such responses as they may be a reaction to extraneous variables. Also, it may be that only one ear of the patient is being tested by playing the sound via loudspeaker due to the fact that one ear cannot be isolated.
Visual Reinforcement Audiometry is used for testing the speech perception of very young children ranging from approximately 7 months to 2 years. The child is inside a sound-proof room. A sound is played. Behavioural conditioning is used as toys and objects at the source of the sound are lit up during every play of the sound in order to condition the child into responding to the sound, for example by turning their head and looking at the object. Eventually, the child learns how they should respond. Gradually, the intensity of the sound and the occurrences of the lit stimuli are reduced until a measurement of the child’s minimum hearing threshold is acquired. When the child is eventually comfortable enough to use earphones without removing them, Conditioned Play Audiometry can be used.
Phobia refers to a cognitive disorder whereby the patient experiences fear of something, usually harmless, so strongly that they are unable to confront it. For example, arachnophobia means the fear of spiders. Those who experience true arachnophobia cannot observe images of spiders without feeling scared and begin displaying physical symptoms such as tenseness, erratic and accelerated breathing and sweating. These are physical signs and symptoms of an anxiety attack. Sufferers of phobias commonly find their lives altered as they avoid what they are unable to confront. For example, Agoraphobics fear being in a place where it would be difficult to escape from, in situations usually considered normal, like a university seminar, a concert or on public transport. Also, Social phobia is the most common disorder in the UK. This phobia refers to a person who is scared of social situations, conjuring up hypothetical results which mean they are too anxious to confront that particular. For example, they may avoid ordering at a cafē for fear that they will say something regarded as embarrassing or unacceptable. People with such phobias know that certain situations might trigger a panic attack for them and therefore they will avoid going outdoors or to social events. Those with any phobia may be unable to partake in activities regarded as normal within their social and working lives, reducing their quality of life. Therefore, a phobia is a common category of an anxiety disorder as they closely share symptoms.
Speech and language therapists need to have good communication and rapport-building skills as they have the responsibility of explaining conditions and implementing therapies to patients. They must ensure their patient feels relaxed and calm, willing to listen and communicate as much as possible and wanting to return to therapy. SLTs also must communicate to colleagues within their career setting. Those working in schools need to be able to inform teachers about students’ speech disorders and recommended therapies. Those in clinical settings need to work alongside nurses and other therapists to implement diagnoses and therapies for speech and swallowing disorders. Thus, the SLT should possess team-work skills including empathy, reliability and conflict-resolution which all assist in building trust amongst peers in the workplace.
SLTs also need good listening skills and patience, as some patients will take longer to show any progress with their communication. There may also be patients simply unwilling to communicate and perhaps even colleagues who are unsupportive or unresponsive. Thus, SLTs must be able to remain calm, empathetic and professional in such situations, for the benefit of themselves, the workplace and the patients.
SLTs also need to have good written English language for writing reports of patients within their case-load. Furthermore, they need to possess strong organisational skills for maintaining and balancing their time, priorities and skills amongst this case-load. Organisation is also imperative as the therapist may be required to visit different school or clinical settings dependent on their role and split their time between many essential roles, such as therapy implementation, report-writing and problem-solving.