Hi, C.!
I wanted to share my experience with you as soon as I read your request. My son, who is now 11, has experienced hearing issues since he was very small. Unlike your daughter, however, my son did experience some slight speech delays in preschool--nothing that significantly impaired his communication--just simple difficulties such as understanding the words of a song, etc.
I would encourage you to stay on top of your daughter's hearing. A reputable ENT/Audiology clinic would be best for follow-up. Look for someone who specializes in children as they are more likely be in tune with a child your daughter's age.
The audiologist will perform the hearing test. For the best results, your daughter will be placed in a sound proof chamber with a window. The audiologist will be located right outside the window and will have visual and hearing contact constantly. They may let you sit inside with your daughter depending on her comfort level, but you will have to remain very quiet and avoid giving her any feedback on how she is doing on the test.
Your daughter will wear headphones, and they will likely do a variety of tests on both ears. They may say words and ask her to repeat them. It is possible that they will place a special microphone behind her ear for certain part of the test. This helps them know if any loss involves the auditory nerve. They may also perform a test that involves blowing air across the eardrum. This will determine whether there is a blockage of some sort that is causing the loss she is experiencing.
Depending on the results, they may choose to re-test after a certain period of time for comparison, or they may suggest some sort of treatment, such as tubes, in the interim.
My son is fairly unusual, and we had to stay on top of the testing for several years before we found someone to truly address his situation. Like your daughter, his loss was in the mild to moderate range, and the idea was that he would "outgrow" it over time. In one-on-one conversations, his problems were not noticeable at all--only in noisy environments, or as you noted in situations where the sports instructor may be farther away or not looking directly at my son's face.
My son has a conductive hearing loss in one ear. One physician has suggested reconstructive surgery, but we are not ready to take that step as the recovery is long, and he may actually lose additional hearing if the surgery does not go well. His auditory nerve is in perfect working order.
In kindergarten and first grades, the school provided an FM system---which is like an amplifier that sits on the child's desk. The teacher wears a wireless microphone so that no matter where she is in the room, the sound is constant for the impaired child. My son also had one-on-one therapy with a hearing specialist to learn techniques to adapt to his hearing loss. The results were amazing!
When he was in the third grade, we had him fitted with a hearing aid--which he wears during school instruction hours. Otherwise, he has done a great job of adapting to the situation and functions very well. We are careful to alert teachers, coaches, etc. to his situation so that they won't assume that he isn't paying attention to them and will provide preferred classroon seating, etc.
The experts suggest that mild hearing impairments are among the most common factors in school behavior problems and classroom performance issues. Hearing impairments can result from allergies to certain environmental issues or foods. You may want to ask the doctor about a simple blood test to determine any allergies your child may have.
You are her greatest advocate! Pay attention to her body language. Does she turn to hear? Does she have to look at people to really understand what they are saying? Does she listen to music or the TV very loudly? Does she ask you to repeat yourself often? Does she gesture when she wants something rather than using words? Communicate all of this information to your doctor.
If your daughter has multiple tests that demonstrate a loss, don't simply walk away, find someone who can help you understand what the loss means and how you can address it. Communicate closely with her teachers at school.
My son went from below average in reading, math, etc. . . to being the top student in his grade level once his problems were addressed. Along the way, several physicians poo-pooed my concerns. The audiologists were my allies and helped me to understand exactly what the losses meant so that I could advocate for my son. No matter how mild a loss is, how your particular child responds to it is what counts! Every person is different.
I know this note is rambling and LONG! My apologies. If, however, you would like any additional resources or information. . . please feel free to send me a personal note. I have learned so much about hearing and children over the past few years--how to handle it in school, issues you may face in other areas, etc. . . that I am happy to share with anyone who is interested.
Good luck with the testing. Regardless of the results, you daughter is lucky that she has a mom who is proactive on her behalf! Best wishes for great results!