These reports have precipitated comparison between ASMR and synesthesia – a condition characterised by the excitation of one sensory modality by stimuli that normally exclusively stimulates another, as when the hearing of a specific sound induces the visualization of a distinct color, a type of synesthesia called chromesthesia. Thereby, people with other types of synesthesia report for example 'seeing sounds' in the case of auditory-visual synesthesia, or 'tasting words' in the case of lexical-gustatory synesthesia.[42][43][44][45][46]
Four months after Novella's blog post, Tom Stafford, a lecturer in psychology and cognitive sciences at the University of Sheffield, was reported to have said that ASMR "might well be a real thing, but it's inherently difficult to research...something like this that you can't see or feel" and "doesn't happen for everyone". Stafford compared the current status of ASMR with development of attitudes toward synesthesia, which he said "for years...was a myth, then in the 1990s people came up with a reliable way of measuring it".[41]
ASMR is usually precipitated by stimuli referred to as 'triggers'.[11] ASMR triggers, which are most commonly auditory and visual, may be encountered through the interpersonal interactions of daily life. Additionally, ASMR is often triggered by exposure to specific audio and video. Such media may be specially made with the specific purpose of triggering ASMR or originally created for other purposes and later discovered to be effective as a trigger of the experience.[4]