Although the five-year-old holds an entry in the Comer Group International Irish St Leger at the Curragh next Sunday, the Newmarket handler has hinted he is likely to drop her back to a mile and half for the Group One prize at Chantilly on the same afternoon instead.
The daughter of Sea The Stars showed her appetite for racing on a soft surface when getting up on the line to claim a mile-and-three-quarter Group Three at Goodwood last time out.
Appleby said: "It is obviously all about the ground with her more so than anything else, so we will keep an eye on how that is.
"Ideally I would like to keep her against her her own sex in the Vermeille and we will take a look at who stands their ground in that.
"If the ground did come right she is more likely to run in the Vermeille than the Irish St Leger."
A step back up to Group Two company to tackle the Flying Childers Stakes at Doncaster beckons for Sound And Silence.
The Windsor Castle Stakes winner defied a penalty to claim his second Listed win of the season in the Roses Stakes at York.
He said: "He looked good switching back to the hold-up tactics applied in the Windsor Castle. They paid off again and it was a good performance under a penalty. Going forward with him we will look to head towards the Flying Childers at Doncaster."
Appleby revealed that Secret Advisor, who claimed victory on the Knavesmire in the Melrose Stakes, is likely to have run his last race of the season after ruling out supplementing him for the William Hill St Leger.
He added: "I was delighted with the result and he replicated the form of his Ascot third in the Queen's Vase.
"I don't think we will be supplementing him for the St Leger. It has never really been the plan, we always had him as a horse for next year.
"He was campaigned towards Royal Ascot and, as he was an unraced two-year-old, we had to get three runs into him before Ascot.
"The soft ground was against him at Goodwood and he appreciated the better ground at York. He has had six runs this year and I feel that is enough for the horse.
"Hopefully he has got a nice career ahead of him and he will make into a nice staying type."