NEW YORK — Barack Obama’s audience for his acceptance speech likely topped 40 million people, and the Democratic gathering that nominated him was a more popular television event than any other political convention in history.

More people watched Obama speak from a packed stadium in Denver on Thursday than watched the Olympics opening ceremony in Beijing, the final “American Idol” or the Academy Awards this year, Nielsen Media Research said Friday. (Four playoff football games, including the Super Bowl between the Giants and Patriots, were seen by more than 40 million people.)

His TV audience nearly doubled the amount of people who watched John Kerry accept the Democratic nomination to run against President Bush four years ago. Kerry’s speech was seen by a little more than 20 million people; Bush’s acceptance speech to GOP delegates had 27.6 million viewers.

Through four days, the Democratic convention was seen in an average of 22.5 million households. No other convention — Republican or Democratic — had been seen in as many homes since Nielsen began keeping these records for the Kennedy-Nixon campaign in 1960. There weren’t enough television sets in American homes to have possibly beaten this record in years before that.