Just quit now. Go to a project that has actual, attainable requirements.
Seriously. I mean, who is doing this? Google (multi billion dollar company with unlimited funds and a brain trust that cannot be matched in most development shops).
Who's not doing it? Yahoo. Bing. Ask. IBM. Liferay. All big companies of varying size that choose not to throw money away on "pie in the sky" projects.
Who else won't be doing it? You.
Let's break it down so it is easy to understand. That little microphone requires speech to text support, a lot of AI and natural language processing, ... Lots of hardware for all of that processing to do the translation before the user just cancels and types in the request.
The cheapest/easiest solution? Let the browser record the query and then ship that to a massive call center for humans to translate into a character-based search query entered on behalf of the user.
