Baby Sound Amplifier and Recorder by Little Martin’s Drawer

"Why we love it – With two hearing options, either by headphone jack or through the amplifier built into the base, the Baby Sound Amplifier and Recorder from Little Martin’s Drawer makes bonding with the child you’re expecting a much more fulfilling experience. Because of this, it is one of the top-rated fetal dopplers on our list."

Source: https://www.mybabiesplanet.com/best-fetal-doppler/