Final answer:
The particular vocal quality that might be a concern for Crystal, the special events coordinator for the American Heart Association, when speaking to 300 11-year-old students in a gymnasium without a microphone is loudness.
Step-by-step explanation:
The particular vocal quality that might be a concern for Crystal, the special events coordinator for the American Heart Association, when speaking to 300 11-year-old students in a gymnasium without a microphone is loudness. Crystal needs to make sure she projects her voice adequately so that all students can hear her. It is important for her to speak loudly enough for the students in the back of the gymnasium to hear her clearly. It would be useful for Crystal to consider using techniques like projecting her voice from the diaphragm and using appropriate room acoustics to ensure that her voice carries throughout the space.