Actually Android standard doesn't include ALSA. There is a thin sound HAL above ALSA, OSS and other Linux sound technologies. Of course many phone vendors use

Actually Android standard doesn't include ALSA. There is a thin sound HAL above ALSA, OSS and other Linux sound technologies. Of course many phone vendors use ALSA to implement Android HAL layer. It seems that Samsung uses its own sound drivers and therefore they have small audio latency compared to other Android vendors.