bullhorn
Longman Dictionary of Contemporary English 5++LDOCE 5++bull·horn /ˈbʊlhɔːn $ -hɔːrn/ noun [countable] 
TD American English old-fashioned a piece of equipment that you hold up to your mouth to make your voice louder 手提式扩音器，喇叭筒 SYN British English megaphone
TD American English old-fashioned a piece of equipment that you hold up to your mouth to make your voice louder 手提式扩音器，喇叭筒 SYN British English megaphoneExamples from the Corpus
bullhorn• I grabbed a bullhorn and yelled, in my most commanding flight attendant voice, for them to back up.• Certain sounds may seem to come out of a bullhorn.• The visible ones grow larger as the fog reflects up at them; their voices become bullhorns.• The cop is saying through his bullhorn that he wants to take the baby.bull·horn nounChineseSyllable
that a up hold you to piece of Corpus equipment
bullhorn
bull‧horn /ˈbʊlhɔːn $ -hɔːrn/
noun [countable]
American English old-fashioned a piece of equipment that you hold up to your mouth to make your voice louder
SYN megaphone British English
bull‧horn /ˈbʊlhɔːn $ -hɔːrn/
noun [countable]American English old-fashioned a piece of equipment that you hold up to your mouth to make your voice louder
SYN megaphone British English