Sense of Hearing Activity 1: Music

Play soothing classic music for your baby during the day when he is playing or at night to calm him down. Relaxing Music such as Canon in D(my favourite) always helps the baby and mummy to sleep better at night as well.

Teach simple actions:
In the day, you can also play nursery rhymes and teach your little one simple actions such as clapping to the rhythm, swaying side to side or even show him how to jump. Try and play songs like "If you happy and you know it" so that there will be a lot of actions that you can show.

Flash cards for songs:
Alternative, I have created flashcards for songs as well and as the songs are playing, I'm flashing the cards to help my little one form the image.

This is part of the set of flash cards for the song "The Bear's Party" which teaches number. 

Simple Games:
Simple games can be played while listening to music. For instance, you can get a ball and place it down the edge of your bed or table when playing the song "Humpty Dumpty" and when the song sings and it "all falls down", roll the ball over and you may actually get a laughter from your little one.