Efficient query-by-example spoken document retrieval combining phone multigram representation and dynamic time warping

•Query-by-example spoken document retrieval (QbESDR) strategies are time-consuming.•A fast QbESDR strategy using different-sized n-grams and inverted indices is proposed.•This was used to select candidates for a dynamic time warping (DTW)-based system.•Score fusion of DTW and the proposed approach is also assessed.•The paper reports effective and efficient solutions for the QbESDR task.