Is 噷 a common way to express thinking? I'm looking for a way to express "hmmn" as in "hmnn... what should I do?" when I stumbled upon 噷. In wikipedia, it says that it is a way to 'indicate thinking' but in baidu, it doesn't appear to have that kind of meaning but rather conveys a sense of dissatisfaction or in a joking manner.

Is 噷 a common way to express the act of thinking or is there a better choice? Something like: [  ]..., 这该怎么办呢？
噷 is not the one you are looking for. 

In Chinese, we usually say 嗯.