Suggested deafness during hypnosis and simulation of hypnosis compared to a distraction and control condition: A study on subjective experience and cortical brain responses.
PLoS One March 4, 2021 Marcel Franz, Barbara Schmidt, Holger Hecht et al.
Hypnosis can alter how people process and perceive sounds, but complete deafness is difficult to achieve. In an experiment with 48 participants, an auditory oddball task was performed under four conditions: hypnosis with a suggestion that an earplug blocked hearing, simulation of hypnosis, distraction by a film, and a control condition. Hypnosis and simulation both reduced target detection rates, response times, and the P3b brainwave amplitude compared to control and distraction conditions. Loudness ratings dropped only during hypnosis. Brain source analysis showed that a small set of neural areas involved in attention, sound discrimination, and response organization accounted for the differences. The authors suggest the term 'hypoacusis' (reduced hearing) is more accurate than 'deafness' for this effect.