US Patent 7589631 Adaptive audio signals in portable communications devices

A method for adapting a characteristic of an audible signal produced by a portable communication device includes obtaining a measure of the normal conditions in the environment surrounding the device. The method also includes obtaining at least one measure from a sensor on the portable communication device as a response to an audible event, where the measure corresponds to the current condition in the environment surrounding the device. The method further includes adapting a characteristic of the audible signal based on the relationship between the current condition and the normal condition and presenting the audible signal to a user of the portable communication device.