Abstract: The present invention relates to a hinge mechanism which provides a tight sound guide joint in a sound guide (13) which is split between a communication unit (11) and a foldable flip part (12). At least two shaft elements (21, 22) pivotally connect the flip part to the communication unit. Each shaft element is arranged in a respective pivot point (26, 27) for the flip part along the pivot axis (25) of the flip part. The sound guide joint is arranged in a first pivot point (26) for the flip part between an opposing surface on the flip part and an opposing surface on the communication unit. The sound guide parts (13a, 13b) are thereby connected to each other irrespective of which pivot position the flip part takes up relative to the communication unit. The hinge mechanism comprises at least one compressive resilient element (32), which, via a shaft element (22) in a second pivot point (27), exerts a force on the two opposing surfaces so that the sound guide joint is pressed together and becomes sound-tight.