Transpositional acoustic frequency range in EAS patients
An electric acoustic stimulation (EAS) hearing system includes a signal processor for processing an acoustic signal input to generate: i. an electrical communications signal representative of an upper electrical range of acoustic frequencies, and ii. an acoustic communications signal representative of a lower acoustic range of acoustic frequencies, the acoustic range including: (1) a lower subrange of acoustic frequencies perceivable by the patient with amplification, and (2) an upper subrange of acoustic frequencies not perceivable by the patient, wherein the signal processor uses frequency transposition to include the upper subrange in the lower subrange. An implanted electrical stimulation subsystem receives the electrical communications signal and delivers a corresponding electrical stimulation signal to auditory neural tissue of an implanted patient. An external acoustic stimulation subsystem receives the acoustic communications signal and delivers a corresponding amplified acoustic stimulation signal to the ear canal of the patient.
1. A method for an electric acoustic stimulation (EAS) hearing system comprising:
processing an acoustic signal input to generate:
i. an electrical communications signal representative of an upper electrical stimulation range of acoustic frequencies characterized by a lowest electrical frequency limit corresponding to a lowest acoustic frequency perceivable by ab EAS system patient via electrical stimulation, and
ii. an acoustic communications signal representative of a lower acoustic stimulation range of acoustic frequencies, characterized by a highest acoustic frequency limit corresponding to a highest acoustic frequency perceivable by the patient via acoustic-mechanical stimulation
wherein the highest acoustic frequency limit and/or the lowest electrical frequency limit are selected to intentionally create a frequency gap of acoustic frequencies not perceivable by the patient, and
wherein the acoustic stimulation range contains acoustic information from the frequency gap based on frequency transposition;
receiving the electrical communications signal with an implanted electrical stimulation subsystem that delivers a corresponding electrical stimulation signal to auditory neural tissue of the patient; and
receiving the acoustic communications signal with an external acoustic stimulation subsystem that delivers a corresponding amplified acoustic-mechnical stimulation signal to the ear canal of the patient.
2. A method according to claim 1 , wherein the acoustic stimulation range contains acoustic information from a lower range frequencies in the frequency gap, and the electrical stimulation range includes acoustic information from an upper range of frequencies in the frequency gap.
3. A method according to claim 2 , wherein the acoustic information from the frequency gap is included in the electrical stimulation range by frequency transposition.
4. A method according to claim 2 , wherein the acoustic information from the frequency gap is included in the electrical stimulation range by frequency compression.