What does emphasis mean in the がして of the following sentence? [duplicate]

Question

I'm translating this old book I have from Japanese to English, and I come across the following sentence.

背後で聞き覚えのある声がして、思わず一歩後ずさってしまった。

I think in the above instance the して is being used to emphasis, as defined by the fourth definition on Jisho.org, shown below.

1. by (indicating means of action); as (a group, etc.)​
2. indicates patient of a causative expression​ - as 〜をして in modern Japanese
3. acts as a connective - ​after the ren'youkei form of an adjective
4. adds emphasis - ​after an adverb or a particle

What does 'add emphasis' mean, and is my understanding of the use of して in the above sentence correct?

EDIT: Added answer to my question: 「して」じゃなくて「する」を調べたほうがいいですよ。#7 to be sensed (of a smell, noise, etc.)​ – Chocolate