Do I have a rooster?

[Saffi0418]

I am new to chicken raising and hope someone can help me.
I have five 8 week old Isa Browns, which I bought as week old chicks. They are meant to be girls, but the breeder said they can't always be 100% right.
I've noticed their 'voices' changing over the past couple of weeks - the 'cheeping' seems to be getting lower in tone, and of course there is the noisier squabbles over food.
They are still inside - in multiple packing boxes joined together, while we finish off the coop. This morning, while they were still covered up, one of them made a noise like a football siren/horn. Would this be the start of crowing, or can the girls also make such noises?

 

[TurtlePowerTrav]

Pics would help, but I think Isa Browns are a sex-link bird(could be wrong, still learning). At 8 weeks may or may not crow if you have a cockerel in the bunch. Their voices do weird things when they start getting the grown up chirps. Could have just been an alarm trill.

 

[gritsar]

Being a sex link breed it's really hard for the sexer to make a mistake, unless there is one chick that was just a tad bit dark for a male and it was sexed as a female. Male day old ISA browns should be white, the females tan.
So assuming that there was that one iffy chick, yes you could be hearing some practice crowing going on.

 

[Chicks on DL]

I was surprised as the peeps turned to deeper clucks and squawks. My Buff Orphington squawks most of the morning and she is definitely a hen. I would not make any judgments until either you hear a cock-a-doodle-doo. Pictures of them would be a better way to make try to make any determination at this age.

 

[Saffi0418]

Thanks - hopefully they are just experimenting.
I cant tell who is responsible for the outburst, but they seem to scare themselves as much as the others!