All puppies are born deaf, gaining the ability to hear around 2 weeks old. Sadly, many puppies never develop hearing, or it deteriorates at a very early age. Owners may struggle to decide whether their new puppy is deaf --- or if they're just being ignored. There is no way to fully test for a puppy's hearing ability at home, but there are some techniques that will give you an indication of any issues.
Jangle your keys loudly while standing behind your puppy, using excited tones to indicate a car ride or walk. There should be some kind of reaction here, but in this case a lack of response could just be a behavioral issue.
Squeak a favorite dog toy, attempting to engage the puppy in play without the visual cue.
Clap and whistle loudly, calling the dog by name from another room. If you get no response, enter the room your dog is in and give it a visual cue. If the dog responds then, you were most likely not being ignored but were instead not heard. The inability to locate the source of a sound is suggested to be one of the only true behavioral symptoms of deafness.
Turn on the vacuum, making sure you are far enough way that the puppy doesn't feel the vibration, but close enough that it would hear the noise if it could. The dog should have some kind of response. If it cowers in fear, barks aggressively or simply perks up in curiosity, you will have some kind of indication that your puppy can hear. If it ignores the noise, than you know there may be an issue.
Walk your puppy past a house where you know there is a barking, aggressive dog inside. Your puppy should not be able to see the other dog, but should hear it. Again you are looking for any kind of response, typically defensive barking or growling. A well trained puppy may ignore another dog, but at a young age there is usually some kind of reaction.
Observe your puppy's play patterns with other puppies. If you're able to observe your dog as part of its original litter, take notice of your pup's behavior. Puppies learn from each other. During playtime a yelp of pain from another puppy is an indicator that play has gotten too rough. A hearing dog would back off at this point, while a deaf puppy may not understand this and would continue the rough play.
Bang two pots together when your puppy is sleeping. Most dogs would respond quickly, even in a deep sleep. If it requires a touch or a bump to wake, it is a strong indication of some kind of hearing issue and seeking veterinarian assistance is advised.