This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
isScoConnected method is used to allow to know if there is a SCO connection between local and the remote Bluetooth device.
var request = instanceOfBluetoothAdapter.isScoConnected();
DOMRequest object to handle the success or error of the operation.
Not part of any specification yet. It should be discussed as part of the W3C's System Applications Working Group.