Final answer:
In ballet performances, ballerinas do not typically wear ear radios. Synchronized swimmers wear earplugs for water-based performances. The difficulty on the mat may be due to the absence of water element affecting their movement and balance.
Step-by-step explanation:
This question is related to the arts and specifically to the field of dance. In ballet performances, it is not common for ballerinas to wear ear radios. Instead, they typically rely on the music being played by an orchestra or a recorded soundtrack, which is projected throughout the theater. The sound is amplified through the theater's sound system, ensuring that the dancers can hear and synchronize their movements accordingly.
In the given information about synchronized swimmers wearing earplugs, it is important to note that this is an exception specific to their water-based performances, where water pressure and submersion can affect their hearing. Therefore, this scenario does not apply to traditional ballet performances, where ballerinas do not typically wear ear radios.
The difficulty the synchronized swimmers experienced when practicing on a mat instead of in water may be attributed to the absence of the water element that affects their movement and balance. Without the water, their movements may feel different and less controlled, making it more challenging to perform their combinations.