Table 7.

Performance of ASR systems when the number of layers in their bidirectional long short-term memory projection (BLSTMP) encoders is different.

Name Number of Layers	PER %
	2	3	4	5
CTC	15.36	14.25	13.34	14.28
Attention	15.25	13.79	13.06	13.87
CTC_Attention ($\alpha$ dynamic adjustment)	13.01	11.24	10.25	11.43