It's not the first time Wing's done bedside duty. There were plenty of refugees at the beginning of the war who needed medical treatment and tending afterward.  He'd even been one of them. Though he had no talent for true healing, care givers were always needed and welcome, and it was a role he fell into well. Sometimes the spark and mind needed healing as much as the body did. 

That's why Soundwave's restlessness, though a concern, is not a surprise. Wing boosts the idle of his engines up a notch to a comforting hum, then matches the tone with a harmonic of his own. It's not singing, he's no talent for that either really, but it is a gentle reminder of a comforting presence. 

Sometimes it helps, sometimes it doesn't.