How to Pronounce the /dʒ/ Sound

/dʒ/ is a consonant in the English language.

As you can see in picture (b), the tongue plays a major part in the production of the /dʒ/ sound. The tongue is raised a bit and its tip touches the roof of the mouth, just behind the upper teeth. The back part of the tongue remains in its place. Note that the uvula blocks the air from moving through the nose. So, the air is blocked behind the tongue and when we lower it down, the air is released forcefully from the mouth. If you pay attention to the circle of the vocal cords in the throat, you can see that it is red, indicating that we must vibrate our vocal cords. So, it is voiced.
In picture (a), the lips are parted and the teeth slightly touch. Note that when you are practicing, it is better to move the corners of your mouth a bit down, just like in the picture.
In picture (c), you can clearly see which part of the roof of the mouth, the tongue tip makes contact with during the sound production. It is marked red. The sound /dʒ/ is represented by the following letters:

As you can see, the /dʒ/ sound can be found in some languages like Hindustani and French, whereas, it cannot be found in several others like Mandarin Chinese, Spanish, Russian, Portuguese, Japanese, Vietnamese, and Korean. However, with all the information provided above, and a little bit of practice, you can easily learn to produce this sound. Look:

Below, there is an audio file that helps you learn the proper pronunciation of the /dʒ/ sound: