One of the biggest sources of new searches in the coming years for Google will come from mobile devices, which is why it is attacking mobile on multiple fronts—with Android phones, mobile apps, and mobile search across multiple devices. One of its more impressive efforts lately has been around voice search. Not every phone has a touchscreen or a full keyboard, and some languages simply aren’t keyboard-friendly, and that is where voice search comes in extra handy.

Google already has impressive voice search capabilities on the iPhone, Android, and other phones in English. But today, it is extending voice search to Mandarin Chinese and to Nokia S60 series phones. There are so many different accents and nuances to spoken Chinese, which is the most popular language in the world, that getting the speech-to-text good enough to return relevant searches is a huge challenge.

I don’t speak Chinese so I can’t evaluate how good a job Google does with Chinese voice search (perhaps some of our readers who know Mandarin can give it a whirl and tell us their impressions in comments). But I am starting to use Google’s English voice search, even though I have an iPhone. The speech recognition in English is surprisingly good.

For instance, just this weekend, driving around Bedford, NY, I remembered that Richard Gere has an inn and restaurant up there, but couldn’t remember the name. Typing in “Richard Gere restaurant” into the Google Maps app on the iPhone returned nothing, so I closed that and clicked on the Google Mobile Apps icon. When I selected search, it encouraged me to try Voice Search. Maybe it always did that, but it was the first time I had noticed it. Already frustrated at that point and not wanting to retype my query, I tried saying “richard gere restaurant.” Sure enough, it understood me and delivered The Bedford Post Inn and Restaurants as the first result.

If Google can get its Chinese language voice search to be that good, China could become its largest source of mobile search queries.