There is no evidence that the Detroit News' radio station, 8XK, had a ringside announcer at this fight--most likely the newspaper received the standard telegraphed summaries, which were then announced over the station.
 
Detroit News, September 4, 1920, page 1:
 
    Fight  Returns  Given  by  Wireless    
    On  Labor  day  afternoon,  Jack  Dempsey  and  Billy  Miske  will  fight  at  Benton  Harbor.
    It  will  be  Dempsey's  first  appearance  in  the  ring  since  he  won  the  championship  from  Willard  at  Toledo.
    For  those  who  are  interested,  returns  on  the  fight  will  be  given  by  the  Detroit  News  radiophone  news  service.  There  will  also  be  reports  on  the  ball  games  and  all  the  other  leading  events  of  the  day.
    For  the  many  wireless  enthusiasts  in  Detroit,  here  is  an  opportunity  to  give  your  friends  and  neighbors  some  real  pleasure.  Invite  them  in  and  keep  them  informed  on  the  news  of  the  day  by  means  of  this  unusual  service.
September 6, 1920, page 1:
 
      Fight  News  by  Radiophone      
________
FOR  the  first  time  a  newspaper  will  announce  by  voice,  carried  by  wireless  today,  the  returns  of  a  heavyweight  championship  fight.  The  Detroit  News  radiophone  this  afternoon  will  call  through  the  air  the  progress  of  the  Dempsey-Miske  battle  at  Benton  Harbor.
        Other  news  of  the  world,  as  it  comes  into  The  News  office,  will  be  sent  out.
     The  News  radiophone  apparatus  will  be  opened  early  and  the  time  intervening  between  bulletins  will  be  devoted  to  concert  music  carried  through  space  from  a  phonograph  in  The  News.
    Wireless  stations  in  and  around  Detroit  are  requested  to  invite  friends  and  neighbors  to  hear.
September 7, 1920, page 1:

Radio  Spreads  Fight  News  Broadcast  in  30  Seconds
_____________
THIRTY seconds after the flash came from Benton Harbor that Jack Dempsey still held the heavyweight championship belt by knocking out Billy Miske in the third round Monday, the result was sent to approximately 300 wireless stations by The News radiophone.
    Fight fans grouped around various receiving stations and telephoned the results broadcast among their friends and thus was Dempsey's victory learned a full half hour before down town bulletin boards received the tidings.
    Operator [Francis] Edwards gave full details of the fight.
    "Fine," was the answer of one station. "We're hearing it distinctly."
    "Hooray for Dempsey," came from another. "Fifteen people are here listening to you. Clearest we've heard you yet."
    From a third: "Simply great. We get every word of it."
REPEATED  FOR  OTHERS.
    The results were repeated for the benefits of other stations that had not tuned in, but a transmitting bulb burned out on the radiophone and the operator was forced to proceed on three-quarters power. Even then various stations heard it distinctly.
    "A little weak but we hear it all right," came from Highland Park.
    This morning a number of amateur enthusiasties who heard the radiophone yesterday afternoon, came to The News building to look at the machine. Said one, a youngster, operator of a wireless outfit on West Grand Boulevard:
JOKE  ON  DAD.
    "Dad went down town to learn the fight returns. He posted them himself by a bulletin board, promising to telephone the news home as soon as he received it. The telephone rang about 20 minutes after I had heard the result from the radiophone. Mother and I had a good laugh at his expense."
    This evening from 8 to 9 there will be another concert given over the radiophone from The News. New phonograph records will be played and, at intervals, news features will be announced. Operators are requested to telephone or write The News regarding results.