A speaking valve for fitment on to a tracheostomy cannula includes a valve unit and an attachment unit. The attachment unit has a tubular housing having a first and a second end and a longitudinal axis extending from the first to the second end. The first end of the attachment unit can be connected to a connector on the tracheostomy cannula and the valve unit is arranged at the second end of the attachment unit. The valve unit and the attachment unit are connected together movably. The valve unit is designed that in a first position it closes the housing of the attachment unit air-tightly with respect to a flow direction, and in at least one second position it permits a flow of air into the housing and out of the housing.