[2] Mutism is typically understood as a person's inability to speak, and commonly observed by their family members, caregivers, teachers, doctors or speech and language pathologists.

Loss of previously normal speech (aphasia) can be due to accidents, disease, or surgical complication; it is rarely for psychological reasons.

[6] Another cause may be a medical condition impacting the physical structures involved in speech, for example, loss of voice due to the injury, paralysis, or illness of the larynx.

[8] Neurological damage due to stroke may cause loss or impairment of speech, termed aphasia.

[9] Trauma or injury to Broca's area, located in the left inferior frontal cortex of the brain, can cause muteness.

For example, there is a spectrum of possible neurobehavioural deficits in the posterior fossa syndrome in children following cerebellar tumor surgery.

Selective mutism is a condition in which the child speaks only in certain situations or with certain people, such as close family members.

[15] Differential diagnosis between selective mutism and language delay associated with autism or other disorders is needed to determine appropriate treatment.

[26][27][28] Intervention services and treatment programs have been specifically developed for autistic children with language delays.

For example, pivotal response treatment is a well-established and researched intervention that includes family participation.

For example, a common method involves the use of pictures that can be attached to velcro strips to create an accessible communication modality that does not require the cognitive or fine motor skills needed to manipulate a tablet.