Playing or listening to music is believed to have several health benefits; one study found it could help improve children's hearing. But even though this research isn't definitive, one company has taken it upon themselves to invent a device that plays music directly to a woman's fetus. The catch? It's inserted into a woman's vagina, just like a tampon.

It's called the Babypod, and it was developed in Spain at a fertility center known as the Institut Marqués. According the company website, the first 100 children born to women using the vaginal speaker have been "normal" and have not experienced any negative side effects. The developers wrote that this device "stimulates major brain structures in human beings [and] it improves their neurological development."

Early stimuli to the brain are important to cognitive development; however, it's unclear if fetal stimulation offers any true advantages. Many expectant parents believe in the power of music, which is why many women will place headphones on their pregnant belly.

In the Babypod, sound is transmitted at 54 decibels — that's equivalent to a quiet conversation. The company says that the silicone product is safe and comfortable, and with rigorous cleaning, it can be used frequently. The company does not, however, recommend this product for women who may have high risk pregnancies.

The device is currently priced at $133 and is meant to be used in conjunction with a smartphone. The small cylindrical device is inserted into the vagina, and if women don't have headphones, they don't need to run out for a pair — its included for the mommy-to-be.