Fig. 1

Left: SONAS® headset. Right: SONAS® device, pre-commercial/trial version. Positioning of the transducers above the temporal bone window on both sides of the head with subject in supine position. 1: headset, 2: transducer, 3: power button, 4: “enter” button, 5: LCD screen, 6: USB port. Size: 19 × 19x12cm. Weight: 2,2 kg