Earlier quoted context omitted.
commercial benefit for copyright is not limited to literally selling things but also covers ads and publicity. the legal system may be asked to consider if a press release for a new model counts as advertising, and if implying a connection to Her was a significant part of said advertisement. the fact that it does not cost money does not make it legal. PETA can't go around running its mouth saying "Beyonce supports PE…
A voice seems to be covered by trademark as opposed to copyright. Two people can naturally have a very similar voice and it would be pretty absurd to have someone not allowed to use their own voice. It isn’t absurd for someone in a specific industry to have their voice protected within that trade.
However, I do not agree that one should be able to stamp out use of any voice one person deems 'too similar' from plying that trade. This would be pretty surprising; it raises numerous questions of fair play, who decides, whether the courts wish to be in the position of making these determinations, and ultimately, I think the balance of equity is against making a broad decision like this, full stop. People have the right to work, and especially have the right to work in a fair environment where they are not unduly taking advantage of other's rights and trademarks.
Marilyn Monroe did not have rights to ban women from blonde curls, or beauty marks, Bettie Page did not have the ability to stop numerous lookalikes from selling pinup photos; this is the same situation.