But for people who continue to stutter into adulthood, researcher Dennis Drayna of the US National Institute on Deafness and Other Communicable Disorders says stuttering can be profoundly disabling.

VOA: standard.2010.02.11

There are about 350 million people all over the world that suffer from disabling hearing loss.

全球听力受损的人,约有三亿五千万。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

There are about 350 million people all over the world that suffer from disabling hearing loss.

全球听力受损的人,约有三亿五千万。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选