Sentence:  Perched securely in the rafters and using a walkie-talkie to communicate with colleagues on the airdock's floor, Lachenmeier was amused to find his voice had risen into the <WSD>Donald Duck</WSD> register due to the bubble of escaping helium spreading along the ceiling. 
Meaning of the word marked with <WSD> tags:  One of the Disney cartoon characters, an anthropomorphic white-feathered duck who usually wears a sailor suit and is known for his voice especially in tantrums.