Like klaxons in action

• Sounding loudly, like a trumpet
• Loud, as trumpets
• Loud, like sirens
• Playing loudly
• Playing loudly, like a group of trumpets
• Like trumpets in a fanfare
• Loud and strident
• With tantaras galore
• Like trumpeting trumpets

Wiktionary Word definitions in Wiktionary
a. In a blaring manner.