Muhammad Ali battled Parkinson's disease his entire post-boxing life. A new study, however, shows that Ali's bout with Parkinson's started well before he was diagnosed with it. Jonathan Eig, who wrote Ali's biography "Ali: A Life" (slated for stores Oct. 3), conducted a study on Ali's speech patterns to determine when his Parkinson's may have first manifested. A copy of Eig's study, which will be presented at Stockholm's Interspeech 2017, was picked up by ESPN's Outside the Lines.

The study found that Ali's speech slowed by 16 percent after a 15-round bout with Ernie Shavers in 1977. Shavers, a brawler, landed 266 punches throughout the fight. Ali's speech normalized over time, but Eig's study, conducted by Arizona State speech scientists Visar Berisha and Julie Liss through CompuBox, Inc., found a downward trend in Ali's speech in the waning years of his career. His speech slowed by 26 percent between the ages of 26 and 39.

The study also found that Ali was slurring his speech in 1978. Ali retired in 1981 and was diagnosed in 1984. Their study sought out to show that speech patterns can be used to trace early signs of Parkinson's. Those involved in the study would like to start using speech patterns to track those at risk of head trauma.

"It's very practical and would be another important step allowing a year-by-year look at brain function," Eig told ESPN. 

Liss concurred with Eig's evaluation. "Speech analytics are a useful tool in tracking the effectiveness of efforts at intervention and in the development of drugs and other treatments for neurological diseases," she said.

Eig added on about the dangers of fighting into later years.

"Ali did damage to himself and he knew it and kept boxing too long, but he didn't have the information we now have about CTE -- you don't have to wait until you're middle-aged to stop," he concluded.