Unfortunately, there are presently many people breeding pit bulls (by whatever variation on that name) who have not bothered to learn anything about the genetic problems of the breed.  There is a significant and growing problem in your breed with deafness.

An effected dog (male) or bitch (female)... one who is deaf... carries the genes for deafness, and if mated to another effected dog is likely to produce all or almost all deaf puppies, and all will carry the genes to produce deafnes in their puppies.... If mated to a carrier, who has half or more of the genes necessary, will produce a high proportion
of deaf and carrier pups. Mating a carrier to an uneffected dog will produce no deaf dogs, and few carriers. There is some degree of variation, depending on the type of heritability of the defect. DNA or RNA test is needed to identify the carriers... but is not yet available... because too many breeders are not aware, are ignoring or don't care.... Developing these tests is not cheap.....

All APBT puppies should probably have BAER testing of hearing before leaving the litter. Any vet can arrange for this testing. This test will spot the pups that has hearing impairment, one deaf ear, or is totally deaf. None of these pups should be bred.