I think the way a spoken language sounds, male or female, also depends on the language, and the country this language is spoken. I grew up with Dutch and German. The German is the way it is spoken on the left side of the river Rhine, and it has a very strong French language influence, because this area used to be part of France for a while. The German spoken there is an up and down experience of intonations, by men and women the same. This means, male and female differences are mostly seen in the frequency. Most any statement sounds like a question.
I can hear a similar difference in Dutch. the Dutch spoken in the northern part of the Netherlands is pretty flat sounding, while the southern Dutch dialekt, which I speak, has a lot of ups and downs, too.
I learned most of my current English from my ex wife, who is a linguist and teaches at a large university. Which means, I learned the more female version of American English. Paired this with the way I used to speak German or Dutch, plus my rather high pitched voice could be the reason that I was able to speak "female" without any real problem. I was around females for most of my time over the last several years, and i just picked up the way they talk. I never had any voice lessons, or did any major exercises for it. I just talked the way it felt tight.
One funny thing though, whenever I use the telephone I use my male voice, sometimes on purpose if I want to push things, sometimes simple because it is a habit.
