Pre-loaded identifiers to identify media content for mobile devices using captured audio

1. A method comprising:

receiving, by a mobile device, first audio content;

generating, by the mobile device, a first digital representation of the first audio content;

accessing, by the mobile device, a data structure stored by the mobile device, wherein the data structure contains at least a second digital representation of at least second audio content;

determining, by the mobile device, whether a degree of similarity between the first digital representation and the second digital representation is within a first similarity interval or a second similarity interval; and

if the degree of similarity between the first digital representation and the second digital representation is within the first similarity interval, sending, by the mobile device and to a remote server, a message comprising data that indicates a match, and

if the degree of similarity between the first digital representation and the second digital representation is within the second similarity interval, sending, by the mobile device and to the remote server, a message comprising data that represents at least part of the first digital representation.

2. The method of claim 1 , wherein determining whether the degree of similarity between the first digital representation and the second digital representation is within the first similarity interval or the second similarity interval further comprises:

comparing the first digital representation and the second digital representation to identify the match by comparing one or more audio coefficients of the first digital representation to one or more audio coefficients of the second digital representation,

wherein an audio coefficient of the one or more audio coefficients of the first digital representation comprises a first value that approximately represents a first audio signal of the first audio content; and

wherein an audio coefficient of the one or more audio coefficients of the second digital representation comprises a second value that approximately represents a second audio signal of the at least second audio content.

3. The method of claim 2 , wherein comparing the first digital representation to the second digital representation further comprises executing, by the mobile device, a matching algorithm, wherein the matching algorithm compares perceptual features of the first digital representation to perceptual features of the second digital representation.

4. The method of claim 3 , wherein a second matching algorithm executing on the remote server is the same matching algorithm executing by the mobile device.

5. The method of claim 2 , wherein comparing the first digital representation and the second digital representation further comprises performing a pre-defined quantity of comparisons.

6. The method of claim 2 , wherein comparing the first digital representation and the second digital representation further comprises comparing a first rate of zero crossings of the first digital representation and a second rate of zero crossings of the second digital representation,

wherein the first rate of zero crossings comprises a first pattern of sign changes of a first function that approximately represents a first audio signal of the first audio content, and

wherein the second rate of zero crossings comprises a second pattern of sign changes of a second function that approximately represents a second audio signal of the at least second audio content.

7. The method of claim 2 , wherein comparing the first digital representation and the second digital representation further comprises transmitting a probability of the match to the remote server.

8. The method of claim 1 ,

wherein each of the first and second similarity intervals comprises a range of degrees of similarity.

9. The method of claim 8 ,

wherein the first similarity interval includes a first range of degrees of similarity,

wherein the second similarity interval includes a second range of degrees of similarity, and

wherein each degree of similarity in the first range is greater than each degree of similarity in the second range.

10. The method of claim 9 , further comprising:

determining, by the mobile device, there is no match between the first digital representation and the second digital representation when the degree of similarity between the first digital representation and the second digital representation is less than the degrees of similarity of the first similarity interval and the second similarity interval; and

if there is no match, refraining from transmitting the message from the mobile device to the remote server.

11. The method of claim 1 , further comprising:

transmitting, by the mobile device, a geographic location of the mobile device to the remote server; and

receiving the first digital representation from the remote server, wherein a relevance of the first digital representation corresponds to the geographic location of the mobile device.

12. The method of claim 11 , wherein the relevance of the first digital representation received from the remote server corresponds to a user profile that includes data associated with at least one of a characteristics or use patterns of a user.

13. The method of claim 12 , wherein the user profile further comprises data including at least one of a user age, one or more user preferences, or one or more user habits.

14. The method of claim 1 , wherein the match indicates the degree of similarity, within a similarity interval, between the first digital representation and the second digital representation.

15. The method of claim 14 , wherein the degree of similarity comprises a ratio of perceptual equivalence between the first digital representation and the second digital representation.

16. The method of claim 1 , further comprising:

storing, by the mobile device, an audio identifier that is received from the remote server, wherein the audio identifier is generated by the remote server and comprises at least the second digital representation.

17. The method of claim 16 , wherein the remote server is capable of recognizing that the mobile device has received the at least second audio content.

18. The method of claim 1 , wherein the first digital representation identifies media content comprising at least one of an advertisement, a product placement, or a media program.

19. The method of claim 1 , wherein the message indicating the match comprises the audio identifier.

20. A computer-readable storage medium encoded with instructions that cause one or more processors of a computing device to perform operations comprising:

receiving first audio content;

generating a first digital representation of the first audio content;

accessing a data structure stored by the mobile device, wherein the data structure contains at least a second digital representation of at least second audio content;

determining whether a degree of similarity between the first digital representation and the second digital representation is within a first similarity interval or a second similarity interval; and

if the degree of similarity between the first digital representation and the second digital representation is within the first similarity interval, sending, to a remote server, a message comprising data that indicates a match, and

if the degree of similarity between the first digital representation and the second digital representation is within the second similarity interval, sending, to the remote server, a message comprising data that represents at least part of the second digital representation.

21. A computing device, comprising:

one or more processors;

at least one module operable by the one or more processors to:

to receive first audio content and generate a first digital representation of the first audio content;

to access a data structure stored by the mobile device, wherein the data structure contains at least a second digital representation of at least second audio content;

determine whether a degree of similarity between the first digital representation and the second digital representation is within a first similarity interval or a second similarity interval; and

if the degree of similarity between the first digital representation and the second digital representation is within the first similarity interval, send, to a remote server, a message comprising data that indicates a match, and

if the degree of similarity between the first digital representation and the second digital representation is within the second similarity interval, send, to the remote server, a message comprising data that represents at least part of the second digital representation.