A wake up alarm providing device (10) is provided, comprising a sound producing unit (11) and a control unit (12), coupled to the sound producing unit (11). The sound producing unit (11) is arranged to provide an audible wake up signal during an alert period. The control unit (12) controls the wake up signal to comprise a diffuse sound during a first part of the alert period and to comprise a localized sound during a subsequent part of the alert period.