John's slight speech impediment made it difficult for his mother to understand him.

约翰轻微的口吃使他母亲难以听懂他。

《柯林斯英汉双解大词典》

It was a man with a speech impediment, and I began imitating him.

打电话的是个口吃的人，然后我就开始模仿他。

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Off the court though, he is seen as dense and dull on account of his speech impediment.

在场上，由于他的言语障碍，他被视为密集和沉闷。

youdao

Researchers say the speech impediment appears to stem from a defectin the gene that regulates the way brain cells break down and recycle waste products.

VOA: standard.2010.02.11

The abnormal gene also was found in 77 unrelated Pakistanis with the speech impediment.

VOA: standard.2010.02.11

Seventy-two years ago tomorrow, a chubby, stoop-shouldered, funny faced man with a speech impediment took a new job.

FORBES: Connect

While the newspaper mockery is not of a genuine speech impediment, for some there's a sense that it might encourage that type of behaviour.

BBC: Roy Hodgson: Is it wrong to mock the way he speaks?

The biggest impediment to this movie is Sandler's speech.

CNN: Review: Sandler should've punted 'Waterboy'