why std.sqrt() is performed twice in utterance_mvn?

[lastsongforu]

I notice in utterance_mvn(), if norm_means is True, then std.sqrt() is performed twice? is there any explanation?

if norm_means:
        x -= mean

        if norm_vars:
            var = x.pow(2).sum(dim=1, keepdim=True) / ilens_
            std = torch.clamp(var.sqrt(), min=eps)
            x = x / std.sqrt()
        return x, ilens