The heartbeat is clearly audible through the built-in loudspeaker with volume control. The ear phone jack enables you to listen through headphones for privacy and you can even record the sounds onto your PC and email them to family and friends.
The fetal heart rate sounds like the hoof beats of a galloping horse. The fetal heart rate usually ranges from 140 to 160 beats per minute, approximately twice the maternal rate (The mothers heart rate can be checked by taking the pulse). You will also hear a rushing wind like sound which is the placenta. In the latter stages of pregnancy you may even hear hiccups and kicks!
It is becoming increasingly recognised by the medical profession that it can be beneficial for mum to be to use a foetal doppler at home in between visits to their GP or hospital. This is particularly the case where mums are anxious perhaps because they have previously had a difficult pregnancy or a miscarriage. It is also a great way for your partner to be involved especially if they are unable to attend your midwife appointments.