grammar - Why did the author use に in the following sentence?

Why did the author use に in the following sentence?

理解しかねて首をかしげる会場の様子に、司会役が「もう少し具体的に」と重ねてたずねた。

たずねる needs に but for animate objects such as human beings. In the above sentence, に is used after 様子 which is an inanimate. Asking to an inanimate object seems to be strange for me.

Answer

This is one of the functions of the particle に; to mark a reason/cause of some action. You can translate that part using "due to", "because of", "on seeing", etc.

デジタル大辞泉 lists this as the seventh meaning of に:

７ 動作・作用の原因・理由・きっかけとなるものを示す。…のために。…によって。「あまりのうれしさ―泣き出す」「退職金をもとで―商売を始める」

This page explains this usage as the 13th meaning of に:

１３　原因・理由を表わすことがあります。
(61)人の多さにびっくりしました。

In your sentence, the chairperson is asking to someone not mentioned in this sentence (presumably, to the speaker on the stage). That person could also be marked with に, but is simply omitted here.

Related questions:

Some verbs take に so often (like ～にびっくりする and ～にあきれる in the link above) that it's perhaps best to just memorize the verb-particle pairs, but that's not the case with your sentence.