Almost a full year behind Spotify, US music streaming service Pandora has finally launched full voice functionality for smartphone users after completing successful beta trials earlier this year. It has a trick up its sleeve to trump its Swedish competitor, however, unveiling a hands-free feature which makes the Spotify feature, and indeed other in-app voice services, look redundant. Like Spotify, Pandora’s voice functionality has been built in-house rather than relying on voice assistants like Alexa, Google Assistant, Cortona and even Bixby. But this as an interesting point because Spotify also has integrations with these proprietary assistants via smart speakers, while a key differentiator (a potentially negative one at that) is that when Pandora began trialing voice in January, it became…