www.doe.in.gov/sites/default/files/specialed/kids.png

Indicators

There can be many signs that a person may not be hearing normally. A few of these signs include:

• being unresponsive to sounds or their name on a regular basis
• asking for things to be repeated or often saying "huh?" or "what?"
• their speech is unclear or there is a delay in developing speech 
• has the volume turned up load for certain things
• has difficulty following conversations involving more than two people
• withdraws from social situations because of difficulty hearing
• answers or responds inappropriately in conversations
• thinks that people sound muffled
• has difficulty hearing in noisy or crowded areas
• hears ringing sounds

http://www.parentcenterhub.org/repository/hearingloss/

Adaptations and Accommodations

• Smile and maintain eye contact while talking to someone who is hearing impaired. If a sign language interpreter is there, talk directly to the person with the impairment, not the interpreter.
• Use complete sentences, especially when talking to children. Good language development is dependent on the correct usage of verbs, adjectives, adverb, nouns, etc. 
• Speak slowly and clearly, but do not exaggerate. Be expressive.
• If a word is not understood, try another word.
• Only use sign language if you are qualified.
• Do not shout. Hearing aids make sounds louder, but they do not clarify the understanding of the sound. 
• If all else fails, use pencil and paper to communicate. 
• During group work, try to seat the person with a hearing impairment so they can see others in the group. 
• Watch the individual with the hearing impairment for facial expressions and body language that will help determine the success of communication. 
• If there is trouble understanding the speech of a person who is deaf, don't hesitate to ask them to repeat what they said. Willingness and desire to communicate is what is most important, not the your ability to understand.

http://ada.ky.gov/hearing_imp_def.htm

Official Definition

The Individuals with Disabilities Act defines hearing impairment as "an impairment in hearing, whether permanent of fluctuating, that adversely affects a child's educational performance but is not included under the definition of deafness".

http://www.specialeducationguide.com/disability-profiles/hearing-impairments/