Baby Crying Detector mode is yet another new feature on Galaxy S5 which alerts you with vibration and flash notification as soon as it detects baby is crying. It also sends a vibration signal to your paired Gear smart watch.
So, to Enable Baby Crying Detector on Galaxy S5, do as follows:
1. Open Settings application
2. Under Personalization menu, touch Accessibility.
3. Open Hearing, followed by Baby crying detector.
4. Now, use the slide button and enable the "Baby crying detector" mode
5. Before using this mode, make sure to read the alert message carefully