Researchers say they’ve come up with an accurate, simple way to monitor breathing while you sleep, no wearables required, reports MIT Technology Review.

A team at Stevens Institute of Technology and Florida State University conducted a six-month study in which earbuds that included an in-line microphone were plugged into an iPhone that recorded sounds as six people slept. The researchers say that even with the earphones placed on a table next to the bed, they were able to use the microphone to monitor participants’ breathing to within half a breath per minute of what could be recorded with a chest-worn respiration monitor and a microphone clipped to participants’ collars.