The New York Times has an interesting article about how we can confront biased speech, and the impact of even the mildest puchback. Some of the suggested responses:
- take ownership instead of going on the attack, say something like "this is bothering me because;"
- respond to the statement as if the person is intentionally being outrageous rather than making the statement seriously; or,
- just change the topic.
One thing the article and researchers note is that doing nothing gives the speaker tacit permission to keep using offensive language.
The article has a lot more to say, and can be found here (article may be behind paywall).