A CRJ200 flight crew aborted their takeoff when they inadvertently activated the Aural Warning test switch as the throttles were advanced. The flight crew cited new smaller airspeed data cards as the culprit.

Narrative

Aborted takeoff. Speed at time of abort less than 20 KTS. Aural Warning Test Switch inadvertently activated upon application of initial takeoff thrust. Immediately after the Captain began to apply the thrust for takeoff we got audio warnings for system problems; there were no associated visual warnings (i.e.; caution or warning messages). We aborted immediately; reviewed the systems; and concluded there was no actual emergency. After all the audio warnings stopped; we exited the runway at Taxiway XX. We then discussed the problem and concluded that the cause for the audio warnings was an inadvertent activation of the 'Aural Warning Test' switch to the up position causing a system test to occur. We believe that the switch got activated by the airspeed data cards getting pushed into the switch by the movement of the thrust levers. Contributing Factors: Company recently updated the airspeed data cards and made them smaller. This allowed the cards to accidentally slip between the thrust levers and the 'Aural Warning Test' switch. The previous version of the cards was taller and would not fit into the space between the thrust levers and the 'Aural Warning Test' switch.