Combine fluency shaping therapy with DAF. Fluency shaping was developed from DAF therapy. Fluency shaping alters your brain’s speech motor control. DAF alters both speech motor control and auditory processing. You need both.

Increase force and volume. Read a motor learning and control textbook. You’ll learn that motor learning (physical therapy, occupational therapy, sports coaching) starts with slow, controlled correct muscle movements. When the patient or athlete has mastered the movement at a slow, gentle speed the force and speed is increased. Increasing force and speed makes the brain learn the motor movements (“muscle memory”). In contrast, fluency shaping leaves you at the slow, gentle stage where you don’t retain the new motor skills. Instead of doing your practice sets in a quiet cubicle, go to an empty amphitheater or a freeway overpass or, like Demothenes, to a beach with crashing waves. Project your voice far and loud.

Talk more! Mastering a new set of motor skills requires massive hours of practice. NBA players practice eight hours a day. Ask your employer for a job that requires talking to people. Helping irate customers on the phone eight hours a day would be perfect! Start a hobby that requires talking, for example, teaching English to immigrants.

Use prolonged speech to talk to strangers. I’d pick up the phone when telemarketers called. I tried to keep them on the phone as long as I could, talking very slowly. They’re getting paid by the hour.