Leaders of the scientific community encourage scientists to learn effective science communication, including honing the skill to discuss science with little professional jargon. However, avoiding jargon is not trivial for scientists for several reasons, and this demands special attention in teaching and evaluation. Despite this, no standard measurement for the use of scientific jargon in speech has been developed to date. Here a standard yardstick for the use of scientific jargon in spoken texts, using a computational linguistics approach, is proposed. Analyzed transcripts included academic speech, scientific TEDTalks, and communication about the discovery of a Higgs-like boson at CERN. Findings suggest that scientists use less jargon in communication with a general audience than in communication with peers, but not always less obscure jargon. These findings may lay the groundwork for evaluating the use of jargon.