A Spanish singer performed to a group of unborn babies when their mothers used a small device to broadcast the music to their wombs.

Eurovision contestant Soraya Arnelas Rubiales - better known by her stage name Soraya - sang All I Want For Christmas Is You and White Christmas while the mums-to-be appeared on stage alongside her.

The ten women danced along to the music as the BabyPod, which is worn like a tampon, transported the decibels up to the womb for the unborn babies to hear.

Eurovision contestant Soraya performed All I Want For Christmas Is You and White Christmas while the mums-to-be appeared on stage with her while wearing the BabyPod device

The BabyPod is inserted into the vagina so the baby is able to hear through the speaker. The foetus is then seen reacting to the music through a sonogram

Soraya said: 'I've never performed for such a young audience.

'The mums were really excited to see what would happen with their babies inside [when they listened to the music].

'It's been a very special day and a very special show.'

Before the concert, the expectant mothers used the BabyPod for their unborn child to listen to classical music.

The device connects to a phone and then plays through a speaker inserted inside the vagina.

It's set at a volume of just 54 decibels – the equivalent to a hushed conversation or soft, ambient music.

A sonogram then captured the change in the babies expressions and the babies mouths moved in time with the classical music.

One mother who attended the special concert called the experience 'unique'.

In October, a study revealed that unborn babies are able to hear in the womb at just 16 weeks gestation.

The device, left, connects to a phone to play music at 54 decibels. Right, Soraya revealed she felt the show was very 'special'

The mothers sat down to hear White Christmas with their devices plugged in and looked moved by the experience

For the first time scientists at the Institut Marques in Barcelona found a foetus is able to detect sounds, and furthermore, that they respond by moving their mouths and tongues.

It was accepted that an unborn baby's ear is fully developed at 16 weeks but, until now, experts did not believe a foetus could hear until between 18 and 26 weeks.

Dr Marisa Lopez-Teijon, who led the study, said the findings show a foetus responds to music transmitted intravaginally by moving their mouth and tongue, 'as if they were trying to speak or sing'.

'When music was applied vaginally, 87 per cent of foetuses moved their mouths or tongues and around 50 per cent opened their jaws very wide and pulled out their tongues to the limit,' she said.

'From the 16th week of gestation, the foetus is capable of responding to musical stimuli.

The mothers joined Soraya on stage for All I Want For Christmas Is You and danced along to the song, with some clutching their baby bumps

During a study by the Institut Marques in Barcelona, researchers found a foetus is able to detect sounds, and furthermore, that they respond by moving their mouths and tongues

'We can therefore say that learning begins in the womb.'

While showing for the first time that foetuses hear as early as 16 weeks, the study also has wider implications.

Researchers note their method could be used to rule out foetal deafness, and allows the parents to ensure their child's wellbeing.

The music stimulates the part of the brain involved in communication, and on hearing the sound the foetus responds with movements similar to vocalisation - the step prior to singing and speaking.

The BabyPod is designed to stimulate learning in this way. It's currently not available to buy in the UK but some clinics offer the service.