Playing sounds in your sleep could be one way to improve your memory, a new study finds.

Researchers demonstrated that the brain undergoes slow oscillations while you're asleep, and playing sounds that are in sync to the movement not only enhances sleep but retains your memory.

"The beauty lies in the simplicity to apply auditory stimulation at low intensities-an approach that is both practical and ethical, if compared for example with electrical stimulation-and therefore portrays a straightforward tool for clinical settings to enhance sleep rhythms," Professor Jan Born, co-author and chair of medical psychology at the University of Tübingen in Germany, said in a press release.

The study was published online in the journal Neuron and exhibits a way people could non-invasively improve brain activity.

The team of researchers performed sound tests on 11 participants during their sleep at different nights; some were given the sync sound stimulations while others received false stimulations that were out of sync with the brain's rhythm.

Those who received synchronized sound remembered word associations from the night before compared to those who were exposed to out of phase sounds.

Music has appeared in a variety of neural studies that detect brain activity. One recent study showed how people were more inclined to buy certain music by following patterns of brain functions.

Previously, researchers have used music as a therapeutic tool for patients battling Alzheimer's disease, the neurodegenerative condition that causes certain pathways to be blocked or crossed to the point where the memory is inaccessible.

"Importantly, the sound stimulation is effective only when the sounds occur in synchrony with the ongoing slow oscillation rhythm during deep sleep," Born said. "We presented the acoustic stimuli whenever a slow oscillation 'up state' was upcoming, and in this way we were able to strengthen the slow oscillation, showing higher amplitude and occurring for longer periods."