Set the belly speaker volume to a low setting - We recommend holding the speaker to your ear and adjust the audio level of the source audio device to a comfortable listening level for you while the speaker is next to your ear. By doing this, what you'd hear is the same as what your baby will hear.Remember that your baby is in a fluid environment and sound travels easily in fluids so you do not need to set it any louder than what you'd want to listen to it if the speaker is next to your ear.You can control the Belly Speaker volume independently of the source audio by adjusting the volume control on the speaker.Once the volumes are adjusted, then apply the sticky gel pad to the speaker and then put the speaker to your belly.If you'd also like to listen to the music/audio you need to connect your headphones to one of the two provided headphone jacks so that you can listen in with your baby. The output from the belly speaker is for the baby, not for the parents.