the given paragraph is :
"The German word was as familiar as it was scary. She heard it often enough before, but it had never been directed at her until now."
In the above sentences, I used the past simple "heard" as a wrong usage of past perfect, so that my students should find out that it is the wrong usage of "had heard" and they could correct the tense.
My question is this; is the past simple "heard" acceptable in the given sentence? My personal opinion is that we should use "had heard" with the past perfect tense in the following clause(had never been directed). But I am an English user as a foreign language so I want to hear what other people think.
Thank you for your time.