Apparatus, systems, articles of manufacture, and methods for viewer authentication are disclosed. An example system includes processing circuitry to execute computer readable instructions to send one or more instructions to cause the user device to: trigger collection of audio metering data from a sensed audio signal based on a programming schedule that is to identify when the program is to be broadcast; accept voting data from the user for a ballot presented in the program; transmit the audio metering data; and transmit the voting data. The processing circuitry also is to determine a level of exposure of the user to the program based on the audio metering data received from the user device; calculate a weighting score based on the level of exposure; and adjust the voting data based on the weighting score.