The study examines the impact of music during colonoscopy on sympathetic - autonomic nervous system, whose activity is operationalized by biopotentials signals. The music is chosen by the patients themselves.

The Null hypothesis: The comparison of the sympathetic - autonomic nervous system (operationalized by biopotentials) intensity between colonoscopy "with" vs. "without" music is not significant.

Alternative hypothesis: The comparison of the sympathetic - autonomic nervous system intensity is significantly higher in colonoscopy "without" music vs. "with" music.

In the field of endoscopy, stress and pain play a relevant role before and during the examination. A variety of methods have been evaluated to date to provide the patient with relaxation/distraction during the examination. Especially the use of relaxation music. However, the previous studies refer to a subjective assessment of the participants after the examination. Here at least one potential bias is to be assumed from the post-procedural euphoria through the use of propofol and/or midazolam. Pain reactions express themselves explicitly in autonomous function. In contrast to our previous work, the present study uses biopotential signals for the objective operationalization of stress reduction.

The activity of the sympathetic - autonomic nervous system is operationalized by biopotentials fixed to the body surface:

• in the face area (corrugator, zygomaticus)
• on the hand (skin conductance, temperature)
• on the torso (electrocardiogram) The satisfaction of the patient and endoscopist with endoscopical procedure were asked using questionnaires.

Inclusion Criteria:

• Indication for colonoscopy
• conscious sedation with propofol
• ASA state 1 or 2

Exclusion Criteria:

• lack of written informed consent
• pregnancy
• General anaesthetics
• ASA state >2
• deafness, Hearing impairment