Consider this: In over five million years of human evolution, only one organ has come to exist for the sole purpose of providing pleasure – the clitoris. It is not required for reproduction. It doesn’t have a urethra running through it like the penis, and thus, does not urinate. Its sole function – its singular, wonderful purpose – is to make a woman feel good!!
Sadly, it is precisely because the clitoris has no function apart from female pleasure that science has neglected to study it as intricately as the penis...
Some suggest the use of binaural beats may increase sexual desire...and there's an app for that.