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 McCainSenate committee to vote Monday on Tillerson Trump fails to mention Clinton in inaugural address Hillary Clinton under microscope at inauguration MORE's (R-Ariz.) Sept. 4 acceptance speech. The addresses by Sen. Barack ObamaBarack ObamaObama's post-presidential vacation delayed by bad weather Trump redecorates Oval Office with gold drapes Trump puts Churchill bust back in the Oval Office 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