It is not rude to touch a deaf person to get their attention as long as you gently tap the deaf person on the shoulder and not on their back.
You should come up to the deaf person in front or the side of the deaf person and gently tap them on the shoulder but do not tap the deaf person on the back as it can startle them.
Being deaf affects speech because the brain of a deaf person is not able to capture the verbal markers.
When you're deaf and cannot hear the vibration in the deaf persons head that is made when speaking is not registered and so it's difficult to know when or if they are getting the accuracy of pronunciation correct.
Also the crispness of speech will deteriorate as the brain and ears are no longer in communication like they normally would be.
Deaf people do not talk properly as they cannot hear the range of sounds they are speaking so they cannot know how they are sounding which makes it hard for the deaf person to speak properly.
The reason deaf people have the voice or funny voices when they speak is because deaf people are not usually able to hear the full range of sounds that people around then with hearing can hear.
This results in the deaf person not being able to always replicate the full range of sounds in their spoken words.
Hearing loss and being deaf can contribute to a lisp because of their inability to hear sounds and imitate them properly.
What is most important is making sure that you watch the lisp and see if therapy is needed.
Interdental and dentalized lisps are the most common in speech development.
The overall product of a deaf speaker's vocal apparatus also depends on the respiratory conditions, laryngeal state, resonators, articulators and prosodic aspects such as intensity, intonation, rhythm, and frequency.
Respiration aspects related to phonation can also be altered in this population.
Some deaf people may even shout when talking because of the inability to hear themselves when talking.
Therefore, persons hard of hearing or deaf unintentionally overcompensate by speaking louder than they ordinarily would.
Unfortunately, there are social implications to this as some people interpret it as rude and uncouth.
Sign language is a completely different language to spoken English and mouth movements used in line with sign language help emphasize particular words or prevent any misunderstanding, as some signs can have multiple meanings.
Although hearing aids and cochlear implants can ameliorate the symptoms somewhat, there are no known treatments to restore hearing, because auditory hair cells in mammals, unlike those in birds or fish, do not regenerate once lost.
Avoid shouting at a deaf person as they cannot hear you unless they are just partially deaf.
Shouting is rude, even to those with hearing issues.
Not only can the shouting come across as aggressive, but for people with sensitive hearing aids, it can suddenly turn things up to 11, becoming very uncomfortable, even painful.