In this paper we introduce an experimental probe based on the transcribed texts of spoken documents stored in the large Czech Radio audio archive of oral documents. This archive contains the largest collection of spoken documents recorded during the last 90 years. The ultimate goal of the project introduced in the paper is to transcribe a part of the audio archive and store the transcription in the database, in which it will be possible to search, and retrieve information. The value of the search is that one can find the information on the two linguistic levels: in the written form and the spoken form. This doubled information-storage is important especially for the comfortable retrieval of information and it extends diametrically the possibilities of work with the information. One of the important issues of the conversion of spoken speech to the written texts is the automatic delimitation of speech units and sentences/clauses in the final text processing, which is connected with the punctuation use important for convenient perception of the rewritten texts. For this reason we decided to test Czech native speakers’ perception of speech and their need of punctuation use in the rewritten texts. The results have served to train program for automatic recognition of speech units and correct supplying of punctuation. For the probe we prepared a mix of texts spoken by typologically various speakers (the length of speech was 30 minutes; 5247 words), these were given to 50 respondents whose task was to supply punctuation to the automatically rewritten texts. We used two special tools to run this experiment; NanoTrans - this tool was used by respondents for the punctuation supply. The other tool for viewing and comparing respondents performance, especially written for the probe, was Transcription Viewer. In the text we give detailed information about these comparisons.