Research indicates that the ISE begins operating within seconds of exposure to intelligible ambient speech — it is an automatic neural response with no warm-up period. Cognitive load increase from continuous auditory suppression accumulates over minutes and hours. The acute onset means that even brief open-floor work sessions are affected; extended sessions compound the effect progressively through the day. This is why the frequency of access to enclosed acoustic spaces — not just their availability — is a meaningful indicator of cognitive work quality in an organisation.