tokens: For English , open source resources to train Kaldi acoustic models as well as language models and a phoneme lexicon exist , in sufficient quality and quantity : TED - LIUM and Librispeech ( 1000h ) allow large - scale training of speech recognizers , with word error rates in the low single digits in their respective domains ( 6.5 WER for presentation speech , 3.2 WER for clean read speech ) .