This is the 1989 Jove mass-market edition I'm reading. I really dig the abstract, fractured images (by Marshall Arisman) on the Jove editions of the series.
Whispers was an irregularly published semi-professional magazine of horror and dark fantasy that Stuart David Schiff published and edited in the 1970s-80s. It was named after a fictitious magazine that H.P. Lovecraft named in one of his early stories in Weird Tales. This sixth and final anthology in the series appeared from Doubleday in 1987, containing stories that had first appeared in the magazine along with some new material. It's probably the weakest volume of the run, but it's not all bad. The book contains fifteen stories including good ones by F. Paul Wilson, Richard Wilson, and Charles L. Grant. My favorites were the ones by David Drake and Manly Wade Wellman.
I found this little, yellowed paperback on my bookshelf. It was published in 1987 and God knows how long I've had it. It touted "pulse-pounding tales of spendid terror," so, I supposed it would be quite pulpy. But, in fact, some very skilled and impressive writers contributed to this collection. It was not nearly as low-brow as I'd anticipated. A story by Lucius Shepard was the stand-out for me, but they were all quite well-wrought and entertaining. Not nearly as nightmarish as the blurb would have you believe.
I think I picked this up at a library used book sale. I didn't have very high expectations of it, but it turned out to have some very cool stories in it. Worth a read if you happen to come across a copy.