Nuance Communications Inc. was downgraded by TheStreet Ratings from “buy” to “hold.” The company’s strengths, it said, include “robust revenue growth, good cash flow from operations and largely solid financial position with reasonable debt,” but it sees “a generally disappointing performance in the stock itself and unimpressive growth in net income.” On Friday, Nuance fell 19 percent. It had adjusted earnings of 35 cents a share, missing the average estimate by 1 cent.