Did he know it was his birthday?

Yesterday was Teddy's 7th birthday.  He spent it at my parents house on Spring Break - playing in the snow and playing golf and basketball.  But did he know it was his birthday?  Sometimes parenting a deaf child with little language is rough.  Yes I KNOW Tariku told him 10,000 times it was his birthday and yes I KNOW my parents told him 1,000,000 times he was 7 but does he know?  Does he understand?  Does he get that he is a year older? Does he understand that Tariku is now 8 and not 7?  Unlike Tariku where we talk and talk about upcoming things we are not there with Teddy yet (I know we will be eventually)  We can't talk to him about the changes of the past year.  I know the time will come when all of these topics will be possible but today as a mom of a brand new 7 year old I wonder what did he like best about being 6, is he excited to be 7 and does he really know what a birthday is?