Undecided voters were more engaged and attentive during the Republican National Convention (RNC) than during the Democratic National Convention (DNC), according to a media research firm.

Uncommitted voters were most engaged in Sen. John McCainJohn Sidney McCainSenate's defense authorization would set cyber doctrine Senate Dems hold floor talk-a-thon against latest ObamaCare repeal bill Overnight Defense: Senate passes 0B defense bill | 3,000 US troops heading to Afghanistan | Two more Navy officials fired over ship collisions MORE's (R-Ariz.) Sept. 4 acceptance speech. The addresses by Sen. Barack ObamaBarack Hussein ObamaGOP rep: North Korea wants Iran-type nuclear deal Dems fear lasting damage from Clinton-Sanders fight Iran's president warns US will pay 'high cost' if Trump ditches nuclear deal MORE (D-Ill.) and Gov. Sarah Palin (R-Alaska) were the second most engaging programs to uncommitted voters. Nielsen also found that likely voters were 12 percent more attentive to the RNC than to the DNC.

McCain's speech drew a hefty 38.9 million viewers, 500,000 more than the 38.4 million viewers who watched Obama's Invesco Field acceptance speech the week before.

The research was conducted by Nielsen AIG, a firm which studies ads, product placement, and program sponsorship during television programs.

-Michael O'Brien