My 7 year old tells me when she wakes up in the morning her hearing is strange. Everybody's voices are echoed and we sound like martians. This started about 9 months ago. Sometimes when we speak she'll say something like "Why are you talking like that?" or "Talk normal. I don't understand!" What could this be, and can it be serious?

Get her checked out by an audiologist.

You may need a referral from your doctor.