Abstract: Neural survival related to a cochlear implant may be assessed by determining stimulus efficacy for both focused and unfocused stimulation at a plurality of locations adjacent nerve tissue; and comparing stimulus efficacy for both the focused and unfocused stimulation at a plurality of locations to determine a measure of neural survival. In particular small differences in effects produced by unfocused and focused stimulation at each of the locations tends to indicate good survival at those locations and conversely large differences in effects of focused and unfocused stimulation at a given location indicate poor survival at that location.

Abstract: Aspects provide methods and sound processor for encoding stimulation signals to convey pitch perception information to a recipient. The method may comprise identifying a first stimulation site based on a selected frequency component of the sound signal that contains pitch perception information, wherein a stimulation signal is generated based on the selected frequency component; determining a second stimulation site adjacent to the first stimulation site; and determining a time delay between when the second stimulation site is independently stimulated with the stimulation signal and when the first stimulation site is independently stimulated with the stimulation signal.

Abstract: Apparatus and method for at least partially fitting a cochlear implant system to a patient is described, comprising: executing a genetic algorithm to select values for a subset of one or more parameters selected from a plurality of parameters for which values are to be selected to fit the implant, wherein said genetic algorithm is operable to generate one or more successive generations of values for said parameter subset; and determining, based on patient feedback, said values of said values for said parameter subset in each of said one or more successive generations.

Abstract: A method for fitting a cochlear implant to a patient. A genetic algorithm operates to generate successive generations of multiple groups of values for a parameter subset, and patient feedback during execution of the genetic algorithm determines the multiple groups of subset values in successive generations. In each generation, half of the groups of values for the parameter subset are selected and used to determine the groups of values for the next generation. Values for the parameters not included in the subset are selected by any traditional method that does not use a genetic algorithm. In one illustrative embodiment of the invention, there are only three parameters in the subset that are selected by a genetic algorithm—parameters relating to rate, number of channels and filtering characteristics.

Abstract: A method for fitting a cochlear implant to a patient. A genetic algorithm operates to generate successive generations of multiple groups of values for a parameter subset, and patient feedback during execution of the genetic algorithm determines the multiple groups of subset values in successive generations. In each generation, half of the groups of values for the parameter subset are selected and used to determine the groups of values for the next generation. Values for the parameters not included in the subset are selected by any traditional method that does not use a genetic algorithm. In one illustrative embodiment of the invention, there are only three parameters in the subset that are selected by a genetic algorithm—parameters relating to rate, number of channels and filtering characteristics.

Abstract: A tinnitus suppression device using an in-the-canal external ear canal pressure regulating device to alter the pressure of the fluid of the external ear canal interior of the pressure regulating device. The device has a body which can be inserted into the external ear canal and which seals the canal from ambient pressure. An adjustably sized body such as a collapsible bulbous portion or a bellows type wall provides a mechanism for altering the pressure in the canal. Either a valve or a mechanical displacement device maintains the pressure differential created.

Abstract: The invention provides an array of electrodes suitable for use as an auditory prosthesis. The array comprises a carrier member formed from electrically insulating flexible material, having a surface and a core, the carrier member including at least a pair of electrodes molded therein, the electrodes comprising a length of contact material formed in a semi-circular shape, having a convex contact surface and a locking portion defining an internal space. The electrode is molded in the carriers so that the convex contact surface of the electrode is preferably flush with the carrier member surface. The locking portion of the electrode is molded into the core of the carrier member in the electrode connected to a lead wire which is molded in the core of the carrier member. The invention further provides a method for fabricating such an array of bipolar electrodes.

Abstract: A method for determining absolute current density through an implanted electrode measures the fundamental and harmonic components of an electrical current passing through the electrode and estimates the absolute current density from the ratio between the magnitude of the electrical current measured at one of the harmonics on the fundamental frequency. Another method of the invention applies a wideband noise input voltage to the electrode under investigation and measures the spectrum of the input voltage and output current to determine a first transfer function. A second transfer function representing an increase magnitude of wideband noise input voltage is also obtained. A difference transfer function is computed and used to determine absolute current density through the electrode. The methods may be practiced non-invasively.

Abstract: An electrical stimulator having a plurality of channels adapted to stimulate bodily tissue with an electrical current on each of the plurality of channels. First and second electrodes are coupled to each of the plurality of channels and adapted to be coupled to the bodily tissue for passing electrical current through the bodily tissue. A first current source and a second current source is supplied for each of the plurality of channels. The first current source being coupled to the first electrode and the second current source being coupled to the second electrode. First and second current sources operate in concert. The value of the current supplied being equal in magnitude and being oppositely oriented for each of the first and second current sources for each of the plurality of channels at any given instant of time. In one embodiment, one of the current sources for one of the electrodes in one of the plurality of channels may be eliminated.

Abstract: An auditory prosthesis using and a signal processor for an electrical input signal designed to represent sound to a person. A plurality of filters each passing a different center frequency is operatively coupled to receive the electrical input signal. Each of the plurality filters is less than critically damped providing an electrical output signal whch has an impulse response which is oscillatory. Thus, the plurality of filters generate a plurality of electrical signals which selectively replicate the temporal nerve discharge pattern of individually located auditory nerve fibers within the cochlea of the person.

Abstract: A multichannel signal processor for and an auditory prostheses utilizing such a signal processor having a plurality of filters each passing a different center frequency providing a set of filtered signals representative of the auditory content of the electrical input signal relative to its respective center frequency. A plurality of gating mechanisms individually coupled to the filter signals pass an output signal at a level above the perceptual level of the person when the filtered signal is above a predetermined level. The predetermined level is individually determined such that the output is past above the perceptual level only when the level of the filtered signal to which the gating means is coupled is likely to be among the larges of the filtered signals of all of the plurality of filters.

Abstract: An electrode adapted to be utilized within the external ear canal for applying/recording electrical signals to/from the neural/neuromuscular system of a person having an external ear canal and adjacent tympanic membrane. The electrode utilizes an elongated flexible body having a proximate end and a distal end. The elongated flexible body is stiff enough to be inserted into the external ear canal but is flexible enough to bend if the electrode is inserted against the tympanic membrane without rupturing the tympanic membrane. A compressible material is mounted at the distal end of the body and an electrically conductive gel is carried by the compressible material. An electrical conductor communicates with the body and electrically couples the conductive gel to the proximate end of the electrode.

Abstract: A method and apparatus for diagnosing the extent of survival of the peripheral sensori-neural elements within the inner ear of a patient by stimulating the patient with one or more pair of electrical stimulus signals having a known amplitude and inter-signal delay, and by measuring the electrical activity within the nervous system of the patient which results from these stimulus signals and comparing the activity which results from the second stimulus signal with the activity which results from the first stimulus signal.