While performing at the 'Stand Up To Cancer Channel 4' charity-show on Saturday, the singer's microphone failed at the start of her performance.
As a result, the TV audience could just hear her voice faintly singing along to a musical backing track, reported Sun Online.
Some viewers said Cole was actually miming to a pre-recorded vocal track that technicians forgot to switch on.
However, the 29-year-old says she was not upset with the tech-issue and carried on until the glitch was fixed and her voice returned midway through the second chorus.
Later she tweeted and blamed "tec issues" for her bizarre whispering rendition.
"I really don't feel upset about the tec issues during my performance and chat... I just hope everyone commenting on it has done their part for the cause."