Why do people with hearing impairments speak slurred or too loudly?

Hearing controls sound reproduction, i.e. tone, timbre of the voice, clarity of sounds, with impaired hearing, this control is impaired.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.