Hoarse voice

Voice disorders can be divided into two broad categories: organic and functional. The distinction between these broad classes stems from their cause, whereby organic dysphonia results from some sort of physiological change in one of the subsystems of speech (for voice, usually respiration, laryngeal anatomy, and/or other parts of the vocal tract are affected). Conversely, functional dysphonia refers to hoarseness resulting from vocal use (i.e. overuse/abuse). Furthermore, according to ASHA, organic dysphonia can be subdivided into structural and neurogenic; neurogenic dysphonia is defined as impaired functioning of the vocal structure due to a neurological problem (in the central nervous system or peripheral nervous system); in contrast, structural dysphonia is defined as impaired functioning of the vocal mechanism that is caused by some sort of physical change (e.g. a lesion on the vocal folds). These types are not mutually exclusive and much overlap occurs. For example, Muscle Tension Dysphonia (MTD) has been found to be a result of many different causes including the following: MTD in the presence of an organic pathology (i.e. organic type), MTD stemming from vocal use (i.e. functional type), and MTD as a result of personality and/or psychological factors (i.e. psychogenic type). ==Causes==

The most common causes of hoarseness is laryngitis (acute 42.1%; chronic 9.7%) and functional dysphonia (30%). (Note that this list is not exhaustive): Employment It has been suggested that certain occupational groups may be at increased risk of developing dysphonia Moreover, physical education teachers, teachers in noisy environments, and those who habitually use a loud speaking voice are at increased risk. However, the exact prevalence rates for occupational voice users are unclear, as individual studies have varied widely in the methodologies used to obtain data (e.g. employing different operational definitions for "singer"). ==Mechanism==

Located in the anterior portion of the neck is the larynx (also known as the voice box), a structure made up of several supporting cartilages and ligaments, which houses the vocal folds. In normal voice production, exhaled air moves out of the lungs and passes upward through the vocal tract. At the level of the larynx, the exhaled air causes the vocal folds to move toward the midline of the tract (a process called adduction). The adducted vocal folds do not close completely but instead remain partially open. The narrow opening between the folds is referred to as the glottis. As air moves through the glottis, it causes a distortion of the air particles which sets the vocal folds into vibratory motion. It is this vibratory motion that produces phonation or voice. In dysphonia, there is an impairment in the ability to produce an appropriate level of phonation. More specifically, it results from an impairment in vocal fold vibration or the nerve supply of the larynx. ==Diagnosis==

The assessment and diagnosis of a dysphonic voice is completed by a multidisciplinary team, such as an otolaryngologist (ear, nose and throat doctor) and Speech-Language Pathologist, involving the use of both objective and subjective measures to evaluate the quality of the voice as well as the condition of the vocal fold tissue and vibration patterns. Definition Dysphonia is a broad clinical term which refers to abnormal functioning of the voice. While hoarseness is a common symptom (or complaint) of dysphonia, Additionally, these measures have been proven to be reliable in a clinical setting. Ratings are used to evaluate the quality of a patient's voice for a variety of voice features, including overall severity, roughness, breathiness, strain, loudness and pitch. These evaluations are done during spontaneous speech, sentence or passage reading or sustained vowel productions. As this technique relies on periodic vocal fold vibration, it cannot be used in patients with moderate to severe dysphonia. The acoustic parameters which can then be examined include fundamental frequency, signal amplitude, jitter, shimmer, and noise-to-harmonic ratios. However, due to limitations imposed by the algorithms employed, these measures cannot be used with patients who exhibit severe dysphonia. Aerodynamic measures Aerodynamic measures of voice include measures of air volume, air flow and sub glottal air pressure. The normal aerodynamic parameters of voice vary considerably among individuals, which leads to a large overlapping range of values between dysphonic and non-dysphonic patients. This limits the use of these measures as a diagnostic tool. Nonetheless, they are useful when used in adjunct with other voice assessment measures, or as a tool for monitoring therapeutic effects over time. == Prevention ==

Given that certain occupations are more at risk for developing dysphonia (e.g., teachers) research into prevention studies have been conducted. Research into the effectiveness of prevention strategies for dysphonia have yet to produce definitive results, however, research is still ongoing. Primarily, there are two types of vocal training recognized by professionals to help with prevention: direct and indirect. Direct prevention describes efforts to reduce conditions that may serve to increase vocal strain (such as patient education, relaxation strategies, etc.), while indirect prevention strategies refer to changes in the underlying physiological mechanism for voice production (e.g., adjustments to the manner in which vocal fold adduction occurs, respiratory training, shifting postural habits, etc.). ==Treatment==

Although there is no universal classification of voice problems, voice disorders can be separated into certain categories: organic (structural or neurogenic), functional, neurological (psychogenic) or iatrogenic, for example. Depending on the diagnosis and severity of the voice problem, and depending on the category that the voice disorder falls into, there are various treatment methods that can be suggested to the patient. The professional has to keep in mind there is not one universal treatment, but rather the clinical approach must find what the optimal effective course of action for that particular patient is. There are three main type of treatments: medical treatments, voice therapy and surgical treatments. When necessary, certain voice disorders use a combination of treatment approaches. Voice therapy is mainly used with patients who have an underlying cause of voice misuse or abuse. Laryngologists also recommend this type of treatment to patients who have an organic voice disorder - such as vocal fold nodules, cysts or polyps as well as to treat functional dysphonia. A combination of both an indirect treatment method (an approach used to change external factors affecting the vocal folds) and a direct treatment method (an approach used where the mechanisms functioning during the use of the vocal folds, such as phonation or respiration, are the main focus) Direct therapies Direct therapies address the physical aspects of vocal production. Vocal hygiene includes adequate hydration of the vocal folds, monitoring the amount of voice use and rest, avoidance of vocal abuse (e.g., shouting, clearing of the throat), and taking into consideration lifestyle choices that may affect vocal health (e.g., smoking, sleeping habits). The toxin acts by blocking acetylcholine release at the thyro-arytenoid muscle. Although the use of botulinum toxin injections is considered relatively safe, patients' responses to treatment differ in the initial stages; some have reported experiencing swallowing problems and breathy voice quality as a side-effect to the injections. Breathiness may last for a longer period of time for males than females. Surgeries involve myoectomies of the laryngeal muscles to reduce voice breaks, and laryngoplasties, in which laryngeal cartilage is altered to reduce tension. ==Epidemiology==

Dysphonia is a general term for voice impairment that is sometimes used synonymously with the perceptual voice quality of hoarseness. It is the reason for 1% of all visits to primary care providers. As there are no anatomical differences in larynges of boys and girls prior to puberty, it has been proposed that the higher rate of voice impairment found in boys arises from louder social activities, personality factors, or more frequent inappropriate vocal use. a condition known to be associated with vocally damaging behaviours. However, a causal relationship has not yet been definitively proven. The point prevalence of dysphonia among the elderly is 29%. Findings regarding the prevalence of geriatric dysphonia in the general population are very variable, ranging from 4–29.1%. This variability is likely due to different methodology used in obtaining information from participants. The most common laryngeal diagnoses among the elderly are polyps, laryngopharyngeal reflux, muscle tension dysphonia, vocal fold paresis or paralysis, vocal fold mass, glottic insufficiency, malignant lesions, and neurologic conditions affecting the larynx. == References ==