The whole Sonic weapon thing was created for the movie. In the books, Prana-bindu training gave the practitioners incredible control over their muscles and nerves, allowing almost unbelievable application of physical skills, including various martial arts.
It was referred to by the Fremen as the 'Weirding Way' of battle, but, in effect, that was just a term to describe the almost mystical control they had over what they were doing. Their combat combined intense physical ability via Prana-bindu training with expert psychology and skillful reading of physical cues from their opponents, as well as a hybrid of many styles of martial arts. (Weirding, in this case, is just a term referring to Mystic Arts of any nature. The etymology is interesting, and I can add it if you are interested.) A large part of what Paul and Jessica taught the Fremen was a limited form of the training; exercises and such to enhance their control over their muscles and nerves, as well as many of the Atreides battle tactics.
Regular Wikipedia actually explains it better than quite a few Dune sites:
Unarmed attacks are part of the specialized martial art called the weirding way, which incorporates the prana-bindu methods of optimized muscle control, which enable one to deliver powerful blows and to move with extreme precision and speed. The basic principle behind the weirding way is that, as Farad'n Corrino says, "My mind affects my reality." A user of the weirding way has to know that the action he or she "wants" to perform has already been performed. For example, to imagine oneself behind an opponent at the current moment in time; when trained well, this knowledge will place you at the spot desired. As the art's prana bindu incorporation allows even small attacks to do massive damage, weirding way combat is to the death.
The closest you had to a 'Sonic Weapon' in the books (at least the early ones) was 'The Voice.' The voice was also not a weapon as shown in the movie, but a demonstration of the above principles of psychology and physical control (in this case, of their voice.) With enough data to work from, the user of 'The Voice' could identify exactly what tones, overtones, intonations and such would most directly trigger immediate responses from the victim; responses that would occur automatically, before the victim could think about what they were doing.
It's basically no different from yelling 'DUCK!' loudly, and in a startled voice; most people will instantly respond -- there is a learned behavior that such a scream indicates danger and a way to avoid it; they don't think -- they just DO it, then think. Extend this idea to people with a phenomenal ability to read cues you give off in response to external stimuli, and add in the ability for them to totally control their voices.. and you have 'The Voice.'
(It also had a more subtle application; much as speech writers know what connotations certain words have on certain audiences, practitioners of the Voice are aware of how to alter their speech to include overtones and such to make themselves more believable, or unquestionable sounding, if they choose. (Or, for that matter, the opposite, if they so choose. Or seductive. Or frighting, etc.) YMMV; long term, it's effectiveness had a lot to do with the target, the skill of the user, and their degree of knowledge of the target.)
As to what a practical application of the Weirding Way looks like.. just watch many old martial arts films; Prana-Bindu training gives them almost perfect control of their bodies; the body does EXACTLY what they want it to.
