The present invention relates to methods and arrangements to enhance transmission quality in a Push-to-Talk system comprising a sending mobile unit MB1, and a receiving mobile unit MB2 used by a receiving subscriber B. The receiving unit MB2 comprises a Play-Out-Buffer POB and a Repeat Buffer RB, whereby a stream of sequences 15-19,25-29,35-39 is sent from the sending unit MB1 to the receiving unit MB2. The method comprises the following steps:—The incoming stream of sequences 15-19,25-29,35-39 is collected into the Repeat Buffer RB and into the Play-Out-Buffer POB. The Play-Out-Buffer has a storage size and a point for commencing play-out that provides low voice delay, and the Repeat Buffer has a storage size that provides high sound quality. —The incoming stream is played-out from the Play-Out-Buffer POB to the receiving subscriber B. —Replay is commenced of a defined part 36-39 of the sequences 15-19,25-29,35-39 collected in the Repeat Buffer RB.