Systems and methods are provided for obtaining statistics from the use of a voice application. The connector assembly defines a port suitable for receiving a proximal end portion of an electrical stimulation lead. Upper edges of the front flaps and lower edges of the lower flaps are sealed by respective upper and lower parts of a patient’s mouth to form upper and lower evacuation channels when the body is disposed within the patient’s mouth. The second diffraction area is adjacent to the first diffraction area and is arranged symmetrically to the first diffraction area with a central line being the symmetric axis.