don't sound them out in your mind.

don't sound them out in your mind.

don't sound them out in your mind.
sound out:
试探(意见),探听(口气)；摸底细;大声读出
因没有具体语境,无法确切判断这句话意思.
可能的意思是：
1 记住不要说出声来；
2 记住不要去试探他们（关于这个事情）.