Listen for the loudest sharpest whipcrack sound.
The waveform should also have a black centre.
Look for the shortest, brightest waveform.
The waveform should be the tallest for that patient.
Ensure the incisors are near to depth markers 1 and 2 for oral insertion.
You should aim to be close to these markers unless the patient is exceptionally tall or small.
Look for the tallest, brightest waveform.
The waveform should be the tallest for that patient.
Sound is not important when focussing the probe.
Try closing your eyes when focussing the probe and listen for the loudest sharpest whipcrack.