While there is no substitute for having a professional health care provider screen your infant's ability to hear, there's nothing wrong with making your own observations at home. In fact, the more attention you pay towards potential problems at home (whether with the child's ears or any other health issues), the faster you can get professional treatment should something be wrong. An audiometric hearing test is not going to do much at that age, so many of the things you can do at home are almost as effective as what can be done in a professional setting. Here are some of the things you can do to evaluate your child's ability to hear.
The first step in evaluation is just to be observant of the child in his or her daily life. This comes naturally to most any mother, of course. If there are loud noises, strange sounds, or disturbances, take note of whether or not the child pays attention to them. If you have reason to suspect a problem, you may even want to begin keeping a journal of sounds and how your child responds to them. This probably is not necessary if there is no reason to think there is something wrong. If the child sees oblivious to sounds that should get his attention, you should take him to a pediatrician for a hearing test.
If you are concerned about your child's ability to hear, you can do more than just wait for a car horn or a door slamming to evaluate his response. One effective hearing test is to situate the child so that he can not see you. Clap your hands a few times loudly and see if the child responds. You can also do the same sort of screening by calling the infant's name or making other loud noises that should get his attention. If you have no reasons to be concerned about the child's ears, you may want to be careful that you do not make noises loud enough to scare the child or, of course, damage his ears.
Work closely with your pediatrician when it comes to your child's ability to hear as well as any other health concerns you might have. Do not feel as though you need to wait until your scheduled appointment to bring up issues you believe to be important. A good doctor will be available for questions and concerns, regardless of when your next appointment is. A regular hearing test is important through childhood, as auditory impairment can lead to a host of developmental delays.