A data output apparatus accumulates received sound data in an accumulating unit (jitter buffer), and reproduces sound based on the accumulated sound data. Then, for a predetermined period of time from the time point at which reception of data starts, the data output apparatus restricts or prohibits discarding of data based on an upper accumulation limit amount as a basis for discarding the accumulated data. Moreover, prior to starting reception of sound data after a transfer of a transmission right, dummy data such as soundless data is accumulated in the accumulating unit. Further, the set values of the upper accumulation limit amount, etc. optimized in the previous communication are stored, and the settings stored in association with a transmitting source apparatus are set as the upper accumulation limit amount, etc. after the transfer of the transmission right.