This paper proposes a discriminative approach to template-based keyword detection.
We introduce a method to learn the distance used to compare acoustic frames, a
crucial element for template matching approaches. The proposed algorithm estimates
the distance from data, with the objective to produce a detector maximizing the
Area Under the receiver operating Curve (AUC), i.e. the standard evaluation measure
for the keyword detection problem. The experiments performed over a large corpus,
SpeechDatII, suggest that our model is effective compared to an HMM system, e.g.
the proposed approach reaches 93.8\% of averaged AUC compared to 87.9\% for the
HMM.