Puberphonia (also known as mutational falsetto, functional falsetto, incomplete mutation, adolescent falsetto, or pubescent falsetto) is a functional voice disorder that is characterized by the habitual use of a high-pitched voice after puberty, hence why many refer to the disorder as resulting in a 'falsetto' voice.  The voice may also be heard as breathy, rough, and lacking in power. The onset of puberphonia usually occurs in adolescence, between the ages of 11 and 15 years, at the same time as changes related to puberty are occurring. This disorder usually occurs in the absence of other communication disorders.
 There is a higher male prevalence of puberphonia, as the voice disorder is characterized by a high pitch that would be inappropriate for the age and sex of the patient. Typically, individuals with puberphonia do not present with underlying anatomical abnormalities. Instead, the disorder is usually psychogenic in nature, meaning resulting from psychological or emotional factors, and stems from inappropriate use of the voice mechanism. The habitual use of a high pitch while speaking is associated with tense muscles surrounding the vocal folds. Assessment and treatment of puberphonia is usually conducted by a speech-language pathologist (S-LP) or an otolaryngologist (ENT). Puberphonia is not a disorder that is likely to go away on its own. Without treatment, the changes in the patient's voice can become permanent. Treatment can involve direct voice therapy, indirect voice therapy, or audiovisual feedback.
 During puberty, changes in the larynx typically result in a decrease in pitch in both males and females. On average, the male voice deepens by one octave while the female voice lowers by a few semitones. The fundamental frequency (pitch) of an adult female typically falls between 165 and 255 Hz and an adult male between 85 and 180 Hz. Anatomical changes during puberty include enlargement of the larynx for both sexes. However, the larynx descends and grows significantly larger in males which often results in a visible laryngeal prominence on the neck (Adam's apple). Additionally, male vocal folds become longer and thicker and resonant cavities become larger. These changes contribute to a deepening of the voice characteristic of pubescent males.
 Puberphonia is characterized by the failure to transition into the lower pitched voice of adulthood. In conjunction with an atypically high pitch, common symptoms include a weak, breathy, or hoarse voice, as well as a low vocal intensity, pitch breaks, and shallow breathing.
 There are a number of proposed causes for the development of puberphonia. The aetiology of puberphonia can be both organic (biological) or psychogenic (psychological) in nature. In males, however, organic causes are rare and psychogenic causes are more common.
 Puberphonia is described as having three main variants, related to the level of anatomical change. The most common presentation of the condition is characterized by a normal adult larynx and an increased pitch due to the vocal folds adopting the falsetto position. A second variant can occur when the laryngeal development is prolonged during puberty. Lastly, puberphonia can occur due to an incomplete transformation of the larynx into the adult form.
 To determine whether a patient presents with puberphonia, a complete voice assessment including medical and diagnostic evaluations is recommended. These assessments are performed by otorhinolaryngologists and speech-language pathologists.
 Puberphonia is most often diagnosed in adolescent or adult male patients. These patients often seek referral to a voice professional because of the social consequences of speaking in the falsetto register. Because a high-pitched voice is not pathologized in women, women are less likely to be referred to clinicians to treat falsetto speech. Some older adult women, however, may seek a referral for this disorder due to increasing weakness of their voice and vocal fatigue at the end of the day (these cases are often referred to as "juvenile voice" or "little girl's voice" rather than puberphonia).
 Puberphonia is a functional voice disorder[citation needed]. To rule out problems in the structure of the larynx as the cause of their voice issues, patients are often referred to otorhinolaryngologists for a physical examination of the larynx and vocal folds. Once physical pathologies are ruled out, a behavioural evaluation can occur.
 A behavioural assessment for puberphonia will consist of several types of tasks, and may include:
 Clinicians can also request a self-assessment, in which the patient describes their symptoms and their effects on activities of daily living. The clinician may direct this self-assessment to include the identification of personality traits that may maintain the disorder, the social and emotional consequences of the symptoms experienced, and whether the patient has any access to their modal voice register.
 A complete assessment for puberphonia or any other voice disorder may require a referral to another healthcare professional, such as a psychologist or a surgeon, to determine candidacy for various treatment options.
 This condition is most often treated using voice therapy (vocal exercises) by speech-language pathologists (SLPs) or Speech Pathologist who have experience in treating voice disorders. The duration of treatment is commonly one to two weeks.
 Techniques used include:
 Indirect treatment options for puberphonia focus on creating an environment where direct treatment options will be more effective. Counselling, performed by the S-LP, a psychologist, or counsellor, can help patients identify the psychological factors that contribute to their disorder and give them tools to address those factors directly. Patients may also be educated about good vocal hygiene and how their behaviour could have long term effects on their voice.
 In puberphonia, the use of audiovisual feedback allows the patient to observe graphic and numerical representations of their voice and pitch. This allows the patient to determine an ideal pitch range based on normative data on age and gender, and incrementally work through speech tasks while working in that desired pitch range. As the patient improves, speech tasks progress to become more natural, involving tasks such as reciting automatic information, to reading, to spontaneous speech and conversation. Incorporating audiovisual feedback in speech and voice therapies has been successful in intervention by improving motivation and guidance.
 In some cases when traditional voice therapy is ineffective, surgical interventions are considered. This can occur in situations where intervention is delayed or the patient is in denial, causing the condition to become resistant to voice therapy.
 There are different types of surgical interventions which have been successful in lowering the vocal pitch in men with puberphonia who had previously received ineffective voice and psychotherapy. The first surgical intervention developed, called relaxation thyroplasty or tetrusion thyroplasty, involves a bilateral excision of 2 to 3 mm vertical strips of thyroid cartilage which lowers the vocal pitch through anteroposterior relaxation and shortening of the vocal folds. It can be performed under local or general anaesthesia.
 Relaxation thyroplasty by a medial approach is a modified approach of traditional relaxation thyroplasty. This version involves lowering the vocal pitch by creating an incision bilaterally in the thyroid lamina and then depressing the anterior segment of the thyroid cartilage.
 A more recent, less invasive intervention is the window relaxation thyroplasty. This approach involves creating a window at the anterior commissure, which is then displaced posteriorly.
 The incidence of puberphonia is estimated to be about 1 in 900,000 population.