15. A system, comprising: a storage device that stores at least one acoustic model of first voice data and at least one acoustic model of transformed second voice data that is transformed from second voice data by a voice transformation function; a converting device that converts at least a part of first text data into first synthesized voice data based, at least in part, on the at least one acoustic model of the first voice data and converts at least a part of second text data into a second synthesized voice data based, at least in part, on the at least one acoustic model of the transformed second voice data as a function of a power spectrum difference between the first voice data and the transformed second voice data; a play-back device that plays the first synthesized voice data via a first speaker and the second synthesized voice data via a second speaker, wherein the first synthesized voice data and the second synthesized voice data are presented substantially simultaneously, and wherein the conversion facilitates distinction of the first voice data from the second voice data; and an interface configured to receive an indication that corresponds to a selection of the first synthesized voice data or a selection of the second synthesized voice data, wherein the play-back device is further configured to generate sounds that represent additional data corresponding to the first synthesized voice data or the second synthesized voice data based on the received indication via the interface.
15. A system, comprising: a storage device that stores at least one acoustic model of first voice data and at least one acoustic model of transformed second voice data that is transformed from second voice data by a voice transformation function; a converting device that converts at least a part of first text data into first synthesized voice data based, at least in part, on the at least one acoustic model of the first voice data and converts at least a part of second text data into a second synthesized voice data based, at least in part, on the at least one acoustic model of the transformed second voice data as a function of a power spectrum difference between the first voice data and the transformed second voice data; a play-back device that plays the first synthesized voice data via a first speaker and the second synthesized voice data via a second speaker, wherein the first synthesized voice data and the second synthesized voice data are presented substantially simultaneously, and wherein the conversion facilitates distinction of the first voice data from the second voice data; and an interface configured to receive an indication that corresponds to a selection of the first synthesized voice data or a selection of the second synthesized voice data, wherein the play-back device is further configured to generate sounds that represent additional data corresponding to the first synthesized voice data or the second synthesized voice data based on the received indication via the interface. 17. The system of claim 15 , wherein the interface is a headset comprising the first speaker, the second speaker, and a gyro sensor that facilitates detection of a leaning motion of the headset as the indication.