Audio based methods and apparatus for detecting a channel change event

An apparatus to detect a television channel change event, comprising:

• an input device to receive a television audio signal;
• a memory to store digital data representative of a first portion, a second portion, and a third portion of the television audio signal;
• and
• a processor programmed to identify at least one of a first muted audio condition or a first transient audio condition in the second portion of the television audio signal, and to identify a channel change event in response to:
• 1) identifying the first muted audio condition or the first transient audio condition;
• 2) failing to identify a second muted audio condition or a second transient audio condition in the first and third portions of the television audio signal;
• and
• 3) determining that a time domain length of the second portion of the television audio signal is greater than a first threshold and less than a second threshold.

A tangible article of manufacture comprising machine readable instructions which, when executed, cause a machine to at least:

• capture a television audio signal having first, second, and third portions, the first portion occurring earlier in time than the second portion and the second portion occurring earlier in time than the third portion;
• identify at least one of a first muted audio condition or a first transient audio condition in the second portion of the television audio signal;
• and
• identify a channel change event in response to:
• 1) identifying the at least one of the first muted audio condition or the first transient audio condition;
• 2) failing to identify a second muted audio condition or a second transient audio condition in the first and third portions of the television audio signal;
• and
• 3) determining that a time domain length of the second portion of the television audio signal is greater than a first threshold and less than a second threshold.