The barring on the forehead has nothing to do with their gender, but rather their age. The younger the Budgie, the further down their forehead towards their cere the bars will be. The less barring there is, or the further up their forehead towards the top of their head the barring is, the older they are.
Usually all baby budgies start out with a light pink cere, and as they get older the cere will either change color or stay pink. This usually happens around 5-6 months old, and by a year old their cere is the color that it's going to be, and is not going to change. So if your Budgies are a year old or older, as you say, then their ceres are the color they are going to say.
Females are sometimes very tricky to sex, males are typically very easy.
I can't tell from the lighting in this photo if this Budgie's cere is a vibrant pink, meaning it's most likely a female, or if it's changed to a shade of purple, meaning it's most likely a male. It appears at first glance to be a female, but the more I look at the color of the cere and the lighting, I can't really tell for sure if it's pink or a shade of light purple. If it's at all purple, then it's a male...
Could you possibly post a photo of the bird straight-on, looking straight at it's face, rather than at an angle like this photo is? That will help tremendously...
In addition, yes, male Budgies tend to be more vocal than females, and most all Budgies that are able to actually talk and say words are male, but there are exceptions to this...And female Budgies can be extremely vocal as far as singing, chirping, etc., so you can't really go buy that. If you told me that this Budgie was saying actual words then I'd go more towards male, but just because it's a very vocal bird as far as singing, chirping, etc., that doesn't tell us anything...