A recorded voice message having a first length and a background sound having a second length longer than the first length are received. The first length of the recorded voice message is determined. The level of a portion of the background sound is lowered, the lowered portion having a length that is substantially the same as the first length. The recorded voice message and the lowered portion of the background sound are interleaved. The length of the background sound is adjusted to the first length plus a third length.