Can a statement be "hissed" without any sibilants?
The verb hissed has several definitions. Chief among them are:
- to make a long “s” sound like the sound that a snake makes
- to say something in a low angry voice
- if people in an audience hiss, they make a long “s” sound to show that they do not like a speaker or performer
All definitions from Macmillan, via OneLook.com.
Now, the fact that the sentence described as being hissed:
You fool!
(a) contains no sibilants (like the sound a snake makes), and (b) is not being performed in front of an audience, constrains the definition to "to say something in a low angry voice".
There's simply no other available definition which suits the context. Therefore, the definition of hissed being employed is #2; the sentence is fine.
One of the definitions of hiss, per Merriam-Webster online:
- to say (something) in a loud or angry whisper
There is no mention of sibilants. Since whisper is certainly not limited to sibilants, either, it stands to reason that the act of hissing can include a phrase without sibilants.
I don't think there can be any grammatical prohibition. We can say, "He kicked a dream" for example and it's meaningless but it's still grammatical.
If you think of someone saying those words it's easy enough to imagine them being sibilant. Try whispering the phrase then whisper it again with an excess of breath. Finally voice it and keep the strong whisper sound. It's impossible to describe accurately in text but it's certainly possible to do and gives an unmistakable impression of vehemence.
To see how other authors have used this in published books you might like to follow some of the links here Google ngram:he hissed,she hissed