9. A method comprising: receiving a speech signal representative of audible speech; processing the speech signal to interpret the speech signal by a dialog system implemented at least partially in hardware; determining, by the dialog system, that the speech signal cannot be correctly interpreted; receiving a noise signal representative of audible background noise; identifying a noise level from the noise signal; determining, by the dialog system, that the noise level is too high for the speech signal to be correctly interpreted; and providing, by the dialog system, a message indicating that the noise level is too high for the speech signal to be correctly interpreted; the method further comprising: storing noise signals received over time; correlating noise signals received over time and failed attempts to interpret received speech signals; and determining a threshold noise level based on the correlation between noise signals received over time and the failed attempts to interpret received speech signals; and using the threhsold noise level to determine that the speech signal cannot be correctly interpreted.
9. A method comprising: receiving a speech signal representative of audible speech; processing the speech signal to interpret the speech signal by a dialog system implemented at least partially in hardware; determining, by the dialog system, that the speech signal cannot be correctly interpreted; receiving a noise signal representative of audible background noise; identifying a noise level from the noise signal; determining, by the dialog system, that the noise level is too high for the speech signal to be correctly interpreted; and providing, by the dialog system, a message indicating that the noise level is too high for the speech signal to be correctly interpreted; the method further comprising: storing noise signals received over time; correlating noise signals received over time and failed attempts to interpret received speech signals; and determining a threshold noise level based on the correlation between noise signals received over time and the failed attempts to interpret received speech signals; and using the threhsold noise level to determine that the speech signal cannot be correctly interpreted. 11. The method of claim 9 , further comprising requesting the noise signal based on determining that the speech signal cannot be correctly interpreted.