Postalveolar Non-sibilants
Non-sibilant sounds can also be made in the postalveolar region. For these sounds, however, the number of acoustically distinct variations is significantly reduced. The primary distinction for such sounds is between laminal palatalized and apical retroflex non-palatalized. (Subapical retroflex non-sibilants also occur but tend to be palatal, as for sibilants.)
Read more about this topic: Postalveolar Consonant