The precise reasons for the fluency-inducing effects of AAF in stutterers are unknown. In stutterers, DAF may produce slow, prolonged but fluent speech. Eventually, many become fully aware of their disorder and begin to identify themselves as stutterers. Under Fraser's presidency, the foundation has published 24 books and 13 brochures for stutterers. Stutterers also use beta blockers to avoid fight/flight responses, hence reducing the tendency to stutter.