The Voicer-kun (ボイサーくん, Boisā-kun) (sometimes erroneously called "Voice-kun") from Koei is an infrared transmitter/receiver for the Super Famicom that connects to the second controller port.
The IR-transmitter is used for controlling Audio CD players, and is able to "learn" IR-signals from different CD Player manufacturers.
The games' package included the Voicer-kun hardware, one or two Audio CDs, and a Super Famicom game cartridge.
Koei also made a number of "Soundware" games for other consoles/computers, which did also include audio CDs or audio tapes.
While using a similar concept, the Voicer-kun games were not part of the Soundware series.