Sensory processing disorders: A child with selective mutism may exhibit high sensitivity to smells, tastes, lights, and sounds. They may experience trouble processing sensory information and shut themselves down to deal with the situation. nnLanguage, hearing, or speech conditions: Disorders of speech, hearing, or language may cause a child to become inflexible as they experience stress during verbal communication.nnFamily background: Raising children in a multilingual or bilingual environment may cause selective mutism. Children who migrate to foreign countries are likely to suffer from selective mutism because of language issues.