When you are viewing the My Baby tab and the weeks of your baby's development, there is a heartbeat sound in the background. If you can't hear this, can you check that your device "mute" switch is not turned on silent mode? (the switch on the top left side of your device)
Also, on the My Baby tab, in the bottom left corner, there is a speaker icon. Can you tap this and make sure this is not set to audio off (the one with a line through the speaker), Also be sure your volume is up when testing this.
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