Are you using the 2.x acoustic model? It is very surprising to me to hear that it has recognition issues that would be attributable to different genders using it, or that this would even be one of the characteristics that would seriously differentiate different user results. What is the sample size you are testing against? This would prompt a need for time-consuming investigation into the reported problem with different genders, so I need to understand a bit more background on why gender seems like the distinguishing characteristic for different recognition results. Thanks.