The tone of the hearing turned tense before the Apple executives appeared, as Sen.

NPR: Apple's Cook Faces Senate Questions On Taxes

More direct evidence from studies of experiments with animals and humans, however, suggests that we may have to alter the very concept of what we mean by hearing loss, and that current tests - particularly pure-tone audiometry which measures our ability to perform "pin-drop" hearing - may not be sufficient to pick up the early signs of a decline in hearing function.

BBC: Viewpoint: Does deafness contribute to dementia?

The hearing also signaled a shift in tone on the part of Congress, where the new Democratic majority has promised a series of hearings on how the industry markets credit cards to consumers.

NPR: Consumer Groups Seek Cap on Credit Card Fees

Does the White House object to the tone and the comments coming from Congressman King, or do you object to the fact that this hearing is being held at all?

WHITEHOUSE: Press Briefing