Hmm, that's curious. I totally looked right past any possible gender aspect on that one. The first impression I got from that form was the treble cleffiness of it. In fact, the more I look at it, the more I can't think of any other design cues other than musical notation. Funny how our minds can latch onto something and then just refuse to let go at times.
I thought about the same thing. I don't know much about notes, but it reminded me of the first one here:
Yes, exactly, that's the treble clef. Also, if we only look at the top half of the speaker, we can see a bass clef (the second one) as well.