Examination of the larynx with a flexible endoscope has been a standard procedure for over 20 years. Although excellent images have been obtained there has not been a method for achieving any objective measurements and there are clearly both research and clinical applications for this. The reason for this is firstly because of the inherent distortion of the lens and secondly because of an absence of a reliable method of assessing the relative position of the endoscope within the larynx. This paper illustrates the theory of how these problems have been overcome and describes the equipment used in the clinical situation. The first clinical trial of the Vocim system is detailed, demonstrating an error of only 4%.