Adele has been put on voice rest after struggling to hit certain notes during her Las Vegas residency. The 35-year-old superstar is currently heading up her ‘Weekends With Adele’ show in Sin City but revealed in her latest run of shows at Caesars Palace that her lack of sleep had stopped her from being able to hit certain notes as she jokingly compared her current vocal technique to that of Ursula from ‘The Little Mermaid’. She told the audience: “I’m sure you can hear it in my talking voice and my singing voice. Your girl was tired. I didn’t sleep very well. “And Ursula from the ocean has com…