Apparatus and methods for including codes in audio signals

A method for including a code having a plurality of code frequency components with an audio signal, comprising:

• producing a first code frequency component;
• producing a second code frequency component separately from the first code frequency component;
• assigning a respective amplitude to each of the first and second code frequency components based on respective abilities of the audio signal to mask the first and second code frequency components;
• and
• including the plurality of code frequency components with the audio signal.

An apparatus for including a code having a plurality of code frequency components with an audio signal, comprising:

• means for producing a first code frequency component;
• means for producing a second code frequency component separately from the first code frequency component;
• means for assigning a respective amplitude to each of the first and second code frequency components based on respective abilities of the audio signal to mask the first and second code frequency components;
• and
• means for including the plurality of code frequency components with the audio signal.

A method for including a plurality of code frequency components with an audio signal, comprising:

• producing a first code frequency component representing a first data;
• producing a second code frequency component representing a second data;
• assigning a respective amplitude to each of the first and second code frequency components based on respective abilities of the audio signal to mask the first and second code frequency components;
• and
• including the first and second code frequency components with the audio signal.

A method for including a plurality of code frequency components with an audio signal, comprising:

• producing a first plurality of code frequency components representing a first data;
• producing a second plurality of code frequency components representing a second data;
• assigning a respective amplitude to each of the first plurality of code frequency components based on respective abilities of the audio signal to mask said each of the first plurality of code frequency components;
• assigning a respective amplitude to each of the second plurality of code frequency components based on respective abilities of the audio signal to mask said each of the second plurality of code frequency components;
• including the first and second plurality of code frequency components with the audio signal.

An apparatus for including a plurality of code frequency components with an audio signal, comprising:

• a processor operative to produce a first plurality of code frequency components representing a first data, to produce a second plurality of code frequency components representing a second data, to assign a respective amplitude to each of the first plurality of code frequency components based on respective abilities of the audio signal to mask said each of the first plurality of code frequency components;
• and to assign a respective amplitude to each of the second plurality of code frequency components based on respective abilities of the audio signal to mask said each of the second plurality of code frequency components;
• and
• a combiner operative to combine the first and second plurality of code frequency components with the audio signal.