In a broad sense, Audiology and Speech Language Pathology is the science and study of communication, hearing and balance. Audiology involves the study, assessment, and management of hearing, hearing loss, and balance related disorders while speech language pathology involves diagnosis and treatment of various communication and swallowing disorders. Although a loosely based understanding of hearing and speech problems was already existent, audiology and speech pathology as a requirement surged after World War II, when noise induced hearing loss and brain injury became a common issue among servicemen.
Who are Audiologists and Speech Language Pathologists and what are their roles as health care professionals?
An audiologist is a licensed professional who specializes in the diagnosis and management of hearing and balance disorders in all age groups, while Speech Language Pathologists (SLPs) specialize in the assessment and management of speech, communication and swallowing disorders, They are usually part of a larger multidisciplinary team that includes Otolaryngologists, Neurologists/Neurosurgeons, Pediatricians, Physiotherapists, Occupational Therapists, Teachers, Psychologists, and other healthcare professionals.
Hearing & Balance:
As a trained professional, audiologists have a comprehensive understanding of the auditory-vestibular systems, and its relevant anatomy and physiology. They possess extensive knowledge about the way sound is produced, transmitted, and perceived, which is crucial for aural habilitation and rehabilitation.
For the assessment of hearing and balance, an audiologist employs various subjective and objective diagnostic tests in the form of a “test battery”. All individuals presenting with hearing and balance symptoms do not have to undergo every single test. The audiologist is required to select an appropriate test battery based on each patient’s individual complaints and health history. Once a conclusive diagnosis is made, the audiologist can provide management options, rehabilitation services, or make referrals to other appropriate professionals.
Types of Hearing Loss:
Hearing loss is usually classified as 3 types: Conductive hearing loss (hearing loss due to issues in the outer and middle ear such as outer ear malformations, ear infections, issues related to the middle ear ossicles, etc.). Sensori-neural hearing loss (hearing loss caused due to problems in the inner ear or the auditory nerve). Mixed hearing loss (a combination of conductive and sensori-neural hearing loss).
The most basic and most commonly used audiometric procedure is the Pure Tone Audiometry (PTA). The test makes use of single frequency tones or “pure tones” given via air and bone conduction pathways to determine the type and severity of hearing loss done across a range of frequencies. Tympanometry or Impedance Audiometry (IA) assesses the middle ear functioning and the mobility of the tympanic membrane in by varying the air pressure in the external auditory canal. Speech Audiometry checks the patient’s ability to identify and repeat sound stimuli at different sound intensities. The results of these tests in conjunction can identify majority of the problems related to the cause of hearing loss.
Otoacoustic Emissions (OAE) and Brainstem Evoked Response Audiometry (BERA) are two objective tests that can be used for screening as well as diagnostic purposes across all age ranges, especially pediatric population. OAE tests the functioning of the cochlear hair cells, specifically the outer hair cells, in response to acoustic stimuli. BERA is a non-invasive procedure that uses electrodes placed on the mastoid and forehead areas to detect electrical activity from the auditory nerve to the inferior colliculus.
Vestibular Evoked Myogenic Potential (VEMP) is a test for vestibular function done by stimulating the ear with high intensity acoustic stimuli and recording the muscle activity via electrodes. There are two types of VEMP – cervical VEMP (cVEMP) tests the saccule and inferior vestibular nerve, while the ocular VEMP (oVEMP) tests the utricle and superior vestibular nerve. Videonystagmography (VNG) measures involuntary eye movements known as nystagmus. VNG uses infrared goggles to track the eye movements during positional changes and a variety of visual stimuli. These tests are valuable tools that assist in the diagnosis of vestibular and balance related disorders such as Meniere’s Disease, Superior Semicircular Canal Dehiscence (SSCD), etc.
Aural Habilitation & Rehabilitation:
After an accurate diagnosis is made, the audiologist will counsel a patient regarding treatment options and make additional referrals to other required professionals. Due to advances in technology, there are a multitude of devices that can prescribed based on patient needs and presenting medical condition. One of the most conventional devices are the hearing aids that can benefit almost all types of hearing loss of varying degrees. There are a vast range of brands and models of hearing aids available today that can be programmed according to patient needs, lifestyle, etc.,
There are also surgical treatment options available for people who receive little to no benefit from amplification devices or are unable to wear them. Middle Ear Implants and Bone Anchored Hearing Implants are surgically implanted hearing devices that convert sound into vibrations to stimulate the middle ear ossicles and the functioning cochlea via bone conduction respectively. Cochlear Implants (CI) and Auditory Brainstem Implants (ABI) are more complex surgical implants. A cochlear implant uses electrodes inserted into the cochlea to directly stimulate the auditory nerve in cases where the inner ear is damaged. In cases where there are malformations or damages to the auditory nerve with or without inner ear problems, an ABI bypasses the cochlea and auditory nerve to directly stimulate the cochlear nucleus in the brainstem.
Research has shown that therapeutic assistance in addition to early intervention is of crucial importance to develop speech, language, and communication skills in pediatric patients. Therapy involves improving auditory and listening skills of the child, as well as training family members to work with the child in different environments and to make maximum use of the hearing device. Adults mostly counselling regarding care and management of their own devices rather than extensive therapy in the absence of other speech or cognitive impairments.
Speech, Language, and Communication:
SLPs usually specialize in the aspect of speech production rather than perception, focusing on a range of communication and swallowing disorders. The problems that fall under the umbrella of speech language pathology include
(i) speech disorders (which is a difficulty with the production of speech sounds) like stuttering, articulation difficulties, voice disorders, and motor speech disorders of neurological origin;
(ii) language and communication disorders that manifest as a difficulty in understanding and using language in appropriate or socially adequate ways;
(iii) cognitive disorders that are usually secondary to traumatic brain injuries, cerebrovascular strokes, and other degenerative disorders;
(iv) swallowing disorders
Assessment and Management:
A complete assessment of speech and language disorders includes comprehensive documentation of patient history along with a wide range of diagnostic tools for an accurate diagnosis across all age ranges. SLPs are required to plan and develop extensive treatment plans based on the assessment as well as monitoring patient progress and adjusting plans accordingly.
SLPs use multiple therapeutic approaches in order to develop an effective treatment plan that need to be tailored for individual needs. Voice therapy uses direct and indirect approaches based on the long-term and short-term goals. Direct approaches involve manipulation of vocal mechanisms for healthy voice production, whereas indirect approaches focus on modifying the environmental aspects such as counselling and implementing healthy vocal hygiene.
Adult neuro-rehabilitation and Swallowing Therapy:
Adult speech and language rehabilitation depends on the type of acquired disorder. Cognitive-communication and speech disorders result in memory issues, slurred speech, weakness of facial and oral muscles, communication and listening difficulties secondary to higher neurological issues. In such cases, the goals may include strategies to prevent further degeneration of memory, tactics to improve coherent speech production and social communication, exercises to strengthen oral motor, and facial muscles. In severe conditions, SLPs may introduce aided communication known as Augmentative and Alternative Communication (AAC).
Difficulty in swallowing is termed as dysphagia. Swallowing requires coordination of the mouth, tongue, palate and esophagus. If even one of these aspects do not function adequately, it causes a difficulty in swallowing. Before management begins, SLPs along with otolaryngologists conduct a comprehensive swallowing assessment including a basic swallow test and Fiberoptic Endoscopic Evaluation of Swallowing (FEES). SLPs will use a combination of compensatory strategies along with direct treatment to improve the swallow function. Compensatory strategies involve improving control over swallowing in order to prevent aspiration while direct treatments use exercises to improve overall range of motion, and strengthening of muscles.
Our Bangalore Skull Based Institute (BSBI) and Bangalore ENT Institute and Research Center (BEIRC) group has a full-fledged audiology and speech department, providing a comprehensive assessment and management of speech, hearing and balance disorders, including Pure Tone Audiometry, Tympanometry, OAE, BERA, VEMP, VNG, Voice and Swallowing Assessment and Management. BSBI-BEIRC-BCIC is a one of a kind, one stop solution for your speech and hearing requirements. To know more about our services visit https://www.beirc.net/ & at https://www.bsbi.info/