Main Research Findings

Many studies have been conducted to identify the causes of voice disorders. For example, thyroidectomy, even when performed without laryngeal nerve injury, can have an impact on both subjective and objective voice quality, potentially leading to changes in voice function and characteristics due to the surgical approach and other factors.

Furthermore, clinical assessments of adenoidal obstruction using a standardized score (the Nasal Obstruction Index [NOI]) have been found to be inaccurate when compared to nasal fiberoptic endoscopy. 4

Benign vocal fold lesions, including cysts, nodules, polyps, and Reinke's edema, are common causes of hoarseness and subsequent voice disorders.

Voice disorders are frequently observed in individuals whose jobs involve extensive voice use. 9

Vocal fatigue is a common symptom among patients experiencing dysphonia. 7

The aging population is experiencing an increasing prevalence of dysphonia, which poses challenges for healthcare systems in managing voice disorders in elderly individuals. 3 11

Voice pathology detection technologies can assist in identifying irregularities in speech signals, potentially enabling early diagnosis of neurological conditions.

Minor structural alterations in the vocal fold cover are significant causes of dysphonia, and treatment can result in improvements in voice quality.

Vocal fold nodules are a prevalent cause of voice disorders in children.

Vocal fold vibration onset delay is commonly observed in spasmodic dysphonia and muscle tension dysphonia.

Vocal tremor, an involuntary tremor of the vocal folds that results in fluctuations in fundamental frequency (f(0)) and/or intensity, leading to an unsteady voice, has been studied acoustically and perceptually. 5

Cerebellar structural differences may be linked to speech impairment in boys and girls with nonsyndromic cleft of the lip and/or palate. 10

Videolaryngoscopy is a valuable tool for diagnosing voice disorders.

Parkinson's disease, a neurodegenerative motor system disorder, commonly affects voice function in patients. 6

Laryngitis, both acute and chronic, is a frequent cause of dysphonia in individuals working in voice and speech professions.

Voice disorders are prevalent in professional voice users, such as actors and singers. 8

Intraoperative neuromonitoring (IONM) during thyroid surgery can protect the recurrent laryngeal nerves, potentially reducing the risk of voice dysfunction.

Geriatric dysphonia, often overlooked, significantly impacts the quality of life in elderly individuals and warrants early detection, evaluation, and management.

Reasons for the Causes

The causes of voice disorders can be attributed to various factors, including abnormalities in the structure and function of the vocal folds, neurological disorders, and vocal habits.

Common Causes

Abnormalities in the Structure and Function of the Vocal Folds

Abnormalities in the structure and function of the vocal folds include vocal fold nodules, polyps, cysts, paralysis, paresis, and inflammation.

Neurological Disorders

Neurological disorders include Parkinson's disease, stroke, cerebral palsy, and amyotrophic lateral sclerosis (ALS). 6

Vocal Habits

Vocal habits include vocal overuse, misuse of the vocal folds, and tension. 8

Other Causes

Other causes include allergies, smoking, alcohol consumption, drug use, stress, hormonal imbalances, and environmental pollution.

Countermeasures for the Causes

Abnormalities in the Structure and Function of the Vocal Folds

Countermeasures for abnormalities in the structure and function of the vocal folds include surgery, drug therapy, and voice therapy. 11

Neurological Disorders

Countermeasures for neurological disorders include drug therapy, rehabilitation, and assistive technology. 6

Vocal Habits

Countermeasures for vocal habits include voice therapy, vocal exercises, and stress management. 8

Comparison Between Studies

Similarities Between Studies

Many studies have in common the use of various research methods to elucidate the causes of voice disorders. It is also common that voice disorders have a significant impact on quality of life.

Differences Between Studies

Studies differ in the types of voice disorders they focus on, research methods, and results. For example, some studies focus on abnormalities in the structure and function of the vocal folds, while others focus on neurological disorders. Research results also vary, including the severity of voice disorders and treatment effectiveness.

Points to Note When Applying Research to Real Life

When applying research results to real life, it is important to consider appropriate countermeasures based on individual circumstances. For example, the cause and severity of voice disorders can vary from person to person. Therefore, it is essential to see a specialist for a proper diagnosis and treatment.

Limitations of Current Research

Research on voice disorders is still not comprehensive enough. In particular, there are many unknowns about the causes, mechanisms, and treatment of voice disorders. Moreover, evaluation methods for voice disorders are not standardized. Therefore, interpretation of research results should be done with caution.

Future Research Directions

To further advance research on voice disorders, the following studies are needed.

• Research to elucidate the causes and mechanisms of voice disorders.
• Research to develop early detection and diagnosis methods for voice disorders.
• Research to develop treatment methods for voice disorders.
• Research to standardize evaluation methods for voice disorders.

Conclusion

Voice disorders can occur due to various causes. If you are experiencing a voice disorder, it is crucial to see a specialist for a proper diagnosis and treatment. Additionally, as research on voice disorders progresses, more effective treatment methods are expected to be developed.