In the TechFest event held at Microsoft few weeks back, Microsoft demoed a prototype Bing app running on Windows Phone 8 device. This upcoming Bing app features a 12-15 percent increase in word error rate accuracy and more.

Here are the improvements over the previous version,

Word error rate reduction

Reduction in latency for speech requests

Better handling of speech requests in noisy situations

Some of the above features are handled at server side and Microsoft is already testing them out in some regions of their Bing Mobile service. I guess the fully improved Bing app will be part of the Windows Phone Blue update coming later this year.

Source: MSFT Kitchen