Compressed speech doesn't take much space anyway. Narrowband AMR uses around 7kbit/s (depending on the desired quality), or ~1 megabyte for a 20 minute call. Th

Compressed speech doesn't take much space anyway. Narrowband AMR uses around 7kbit/s (depending on the desired quality), or ~1 megabyte for a 20 minute call. The quality isn't great, but it's adequate for most purposes, including speech recognition with reasonable accuracy.