Speech is a communicative skill that enables us to understand each other and to interact. It becomes a means of communication, allowing us to share ideas, beliefs, and opinions. When this process is disrupted, and the normal flow of receptive and expressive aspects of speech is compromised, a speech assessment is carried out to assess the disturbance. Disturbances of speech can come in the form of content formation (i.e., the patient has difficulty expressing the desired ideas in the form of spoken words) or of articulation (i.e., the patient can express their ideas in spoken form but has one or more problems physically producing the sounds necessary for intelligible speech). A speech assessment, together with formal neurological evaluation, can identify specific speech problems or patterns of speech problems, as well as propose solutions.[1]

Speech assessment is a method to evaluate and diagnose problems in adults and children of speaking, swallowing, comprehension, and writing. Such evaluation may be warranted due to neurological diseases, stroke, trauma, injury, tumors, cerebral palsy, cleft palate, orofacial musculature, hearing impairment, stammering, articulation errors, motor speech disorders, and many other conditions.[2]

Formal speech assessment is performed by a trained speech and language pathologist, and begins with a consultation in the office with the patient and potentially with family members. Reviews of prior records and treatment will be conducted, and formal characterization of receptive and expressive speech will be conducted, including articulation, fluency, content, and clarity of speech, and potentially evaluate breathing and swallowing. Objective testing such as videostroboscopy, nasometry, or rhinomanometry may be obtained, depending on the specific disorder under investigation.[3]

Speech is the verbal expression of thoughts and ideas. In many cases, speech is used to communicate via a shared language. Language is an agreed-upon rule-based code we use to communicate. Parents may present with a range of concerns regarding their children when they choose to consult a speech-language pathologist (SLP). These may include but are not limited to, the child’s patterns of speech, cognitive, and social skills in contrast to their peer group. Some parents may be concerned that their child does not match up to other children their age and appears to be lagging in milestones. These may include behavioral and hearing issues also.

Multiple tests have been devised to assess oral motor disorders. One of them is the Fletcher time-by-count test of diadochokinetic syllable rate. The diadochokinetic (DDK) rate is an assessment tool used by SLPs to measure the repetitions of sounds within a set period of time. It measures how rapid one can correctly repeat a series of rapid, alternating sounds. These are called 'tokens.' Words with one, two, or three syllables are included in tokens. For e.g. 'puh', 'puh-tuh', or 'puh-tuh-kuh'. DDK rates vary between different age groups and patients with varying neurological conditions.[4]

Normal speech depends on the functional and structural integrity of the velopharynx. This is a complex and dynamic structure that uncouples the oral and nasal cavities during sound production. Dysfunction of the velopharyngeal valve leads to hypernasality, nasal air emission, and compensatory articulation errors, all of which may impair speech intelligibility. Functional voice disorders also come under speech pathology and therapy services, in both professional and casual voice-users.

When we speak or swallow, a thin sheet of musculo-mucosal tissue called velum disunites the oropharynx and nasopharynx during speaking and swallowing. Cleft palate is a congenital deformity commonly causing velopharyngeal insufficiency (VPI), though VPI can exist independent of cleft palate also. VPI compromises speech sounds, decreases the comprehension of speech and swallowing efficacy due to improper closure of soft palate that is closed during swallowing and speaking. If the velum is not closed fully against the posterior wall of the pharynx at Passavant's ridge, this poor closure will result in nasal regurgitation and resonance disorders (hypernasality and/or hyponasality).[5] 

Speech pathologists continue to develop rehabilitative strategies under swallowing management programs also. As speech and swallowing rely on many of the same sensory and motor facilities, they are necessarily related. Oral medications may also need modification in texture so the patient can swallow them safely. Likewise, daily diet modifications may be required in patients suffering from dysphagia. As patients progress through such swallowing management programs, nasogastric tube feeding, a percutaneous endoscopic gastrostomy may also be suggested via speech assessment depending on the type and severity of swallowing difficulty. Swallowing difficulties are also very common in neonatal populations, and there is a distinct sub-specialty of speech pathology dedicated to neonatal feeding. Since speech assessment is a multifactorial process, it is inclusive of the individual, their family history, health, and socio-economic status enabling insight into the circumstances relevant to individual patients' needs. For example, a child who is not responsive to the parents' or the clinician’s verbal commands may be suffering from hearing impairment, or other auditory dysfunctions. Autism Spectrum Disorder and other disorders might also be underlying issues that have not been diagnosed prior, but can be elucidated through a thorough speech assessment. Clinical conditions and communication disorders are coexisting conditions in cases of cleft palate, hearing deficit, traumatic or congenital brain injury, and anomalies of the orofacial structure and difficulty in deglutition (dysphagia).[6][7]

Milestones are the markers that represent a standard of normal development, and there are well-defined speech, swallowing, and language skills milestones. If a child’s speech, understanding, cognition is not age-appropriate or is not like their peer group, then further investigation is warranted. There are many potential culprits, and a formal assessment of the child's hearing ability, cognition, anatomy, and home/family environment will be investigated.

Speech assessment, through its multifactorial approach, includes the child or individual’s family history, health, and socioeconomic status. It gives an insight into the circumstances they stem from, including cultural and ethnic backgrounds, which is especially relevant in multi-lingual households.[8]

A child, for example, who is not responsive to the parents or the clinician’s verbal command, may be suffering from hearing impairment or other auditory dysfunctions. Autism Spectrum Disorder and other disorders might also be underlying issues that have not been diagnosed but can be done so through thorough speech assessment. Clinical conditions and communication disorders are coexisting conditions in cases of cleft palate, hearing deficit, traumatic or congenital brain injury, and anomalies of the orofacial structure and difficulty in deglutition (dysphagia).[9]

SLPs are trained in the management of swallowing disorders as well, and there is a significant overlap with speaking difficulties. In addition to the phonatory functions of the vocal folds, they serve a protective function during deglutition. Impaired oropharyngeal phase leads to aspiration of saliva or other pathogens, including liquids/food. Poor bolus control or weak oral musculature can affect the optimum intraoral pressure that is essential for food propulsion in the esophagus. Patients with neurologic deficits may have poor oral hygiene, which acts as a medium for bacterial and fungal growth. Oral thrush is a common finding in hospitalized patients that have suffered from cerebral vascular accidents or have other neurological conditions that have impaired their speaking and swallowing ability. SLPs are consulted before a patient is started on a solid or semi-solid diet. A proper bedside swallowing test can give a general risk of aspiration in the patient.[10]

Acquired swallowing disorders are prevalent among intensive care unit (ICU) patients. Such patients face potential malnutrition, as well as problems with the administration of medications. A speech-language pathologist assesses all stages of the swallowing mechanism. In the case of poor oral hygiene, there is an increased chance of vulnerability for developing dysphagia. Early detection of oropharyngeal dysfunction will improve the prognosis and outcome of patients as they say early intervention leads to an early cure in most cases.

In the ICU, when patients are extubated, the first oral intake trial for the assessment of intact swallowing efficacy is conducted by the speech-language pathologist, after which they give the go-ahead for the provision of safe and smooth oral feeding. If any physical symptoms of deglutition are found like coughing, throat clearing during or after the oral trial, or drop in saturation, other ways of feeding are then recommended to fulfill nutritional requirements and medication intake. Rehabilitative strategies are also guided to improve the strength of oral musculature.[11]

Silent aspiration is another important feature when dysphagia is addressed. Patients suffering from dysphagia do not exhibit noticeable symptoms of swallowing difficulties. The observers that include nursing staff, attendants, and even primary consultants are not unaware of the fact that food particles and liquids have entered in patient’s lungs. Specially trained speech pathologists can suggest videofluoroscopy, also known as a modified barium swallowing test.[12]

Stroboscopy is a method of examination of a fast-moving vibrating object, such as the vocal folds. A bright flashing light lasting a fraction of a second (10 microseconds) illuminates the vocal folds. It 'freezes' the movement of the vibrating vocal folds when synchronized with a known frequency of vibration of normal vocal folds. SLPs are trained in the management of swallowing disorders as well, and there is a significant overlap with speaking difficulties. The diagnostic practice of SLPs has been revolutionized by high-speed digital imaging. This method runs at 4000 frames per second. This rate is fast enough to easily visualize the complete movement and behavior of the vocal tract. Multiple procedures like nasometry, stroboscopy, videofluoroscopy, vital stimulation therapy aid in the assessment of speech and swallowing disorders, and improving patient outcome.[13][14]

Nasometry is a method or term used to describe noninvasive techniques for measuring the size of the velopharyngeal opening. During the articulation of speech using vowel sounds, nasometry measures the nasalance of speech. The nasality of speech is usually determined by the size of the velopharyngeal opening.[15]

Speech-language pathologists are essential components of the interprofessional team caring for patients with voice or swallowing complaints. This team will often include one or more physicians, nurses, occupational therapists, physical therapists, mid-level providers, and many others.[16] Working in collaboration and communication with each other will help in early identification of patients in need of SLP evaluation and therapy, and help improve patient outcomes. [Level 5]