Toslink Optical Splitter 1 in 2 Out Audio Adapter Cable, EEEkit Digital Optical Fiber Optic Splitter with 24K Gold Plated Connectors for CD/DVD Player, Digital TV, Receiver, Sound Bar, Amplifier - Walmart.com
Best Headphone Splitters 2020: How Do They Work? How to Split Devices
Amazon.com: DIGITNOW Headphone Splitter,3.5mm Extension Cable Audio Stereo Y Splitter (Hi-Fi Sound), 3.5mm Male to Female Dual Headset Jack Adapter for iPhone Samsung Tablet Laptop, PS4, Switch & More : Electronics
Recording to Garageband with a audio splitter cable - ticking noise : r/volcas
Sound through the earphone is also sent to the amplifier when using a jack splitter after a audio mixer - Electrical Engineering Stack Exchange