The use of Speechmatics to obtain a printed text is a great saving on employing a stenographer to do the work. I have experimented with different files to obtain the most correct printed text from the voice. Speechmatics themselves say that a good level is essential for the system to work. Strangely the results do vary enormously.. One male voice can sound very similar to another but the resulting text print out can be totally different. By way of experiment I recently tried a female archive voice and only used one side of the recording. The result I think was slightly better in that A) The female voice works better with Speechmatics anyway and B) The use of one side of the recording produced near perfect results especially when there were few technical terms and/or proper names. It is always worth an experiment to do a short before getting the whole interview processed.