O'Neill's side drew 0-0 in their opening game of the season at Arsenal on Saturday and the Black Cats manager has admitted he wished he could have had some new signings in before the season started.
O'Neill told Sky Sports: "We would have liked to have had some players in before the Arsenal game, but that did not happen.
"We have a lot of spirit about us, but lack quality in some positions. We need some better attacking options.
"It has been slow, perhaps people's attentions have been elsewhere with a fantastic Olympic Games, but maybe now there might be that bit of movement.
"Maybe some of us were waiting for bigger teams to move, then we pick up, but I should not really concern myself with what other clubs are trying to do, because I am trying to do the best for us."
Sunderland added Louis Saha to their squad before the opening day of the season, but O'Neill has admitted he is looking to bring in a younger player, with the North East club already having offers turned down for Wolves striker Steven Fletcher.
He added: "Fletcher has been one of the players mentioned, but we need to strengthen because we need some help.
"There were little moments where Louis Saha showed his class, but expecting a 33-year-old to come in and play X number of games for us is out of the question.
"I am hopeful we are able to do something."