Why is the Sound of Cicadas so Unique?

[wilsonlam97]

Here's a Toronto Cicada. I'm used to this one but I've heard some different ones. What's up with that? When I hear them I know it's effin hot out there. Is it possible to tell the temperature by the sound of Cicada's?

[woof]

I believe the primary purpose of the sounds that they make is to attract mates.

[asennad]

I hate the damn things. Always reminds me that the summer is coming to an end.

[Matrixvibe]

ohhhhh, so these things make those sounds!

[Jimboski]

These dudes are annoying!

[woof]

That's probably what they say about us when they hear us talking.

[nikkiishappy]

I believe the primary purpose of the sounds that they make is to attract mates.

I heard them this morning and I was wondering what that noise was...

How does it indicate that summer is coming to an end?

[aqnd]

They don't directly indicate it. Just that they've fully grown and it's damn hot out when you hear them, so you know summer is past the peak and it's downhill from here :p