quavered的音标？

He quavered out folk songs.他以颤声演唱了民歌.Her voice quavered and she fell silent.她声音发颤然后便默不作声了。She quavered an old folk song.她以震颤声唱一首古老的民谣....

v.发颤音，（声音或音乐）颤抖( quaver的过去式和过去分词 )，用颤抖的声音说...