Stochastic stimulation in a hearing prosthesis

Abstract

A method, for inducing a hearing percept to a recipient of a cochlear implant, includes: building a sequence of electrical stimulation pulses having first and second inter-pulse intervals; and making stochastic the sequence including randomly selecting either the first or the second inter-pulse interval for insertion between consecutive pulses in the sequence.

1 . A method for inducing a hearing percept to a recipient of a cochlear implant comprising:
 building a sequence of electrical stimulation pulses having first and second inter-pulse intervals; and   making stochastic the sequence including:
 randomly selecting either the first or the second inter-pulse interval for insertion between consecutive pulses in the sequence. 
   
     
     
         2 . The method of  claim 1 , wherein the revising includes at least one of:
 limiting the number of consecutive instances of the same inter-pulse interval;   selectively changing instances of one of the first and second inter-pulse intervals for the other thereof in order to substantially balance the distribution of the first and second inter-pulse intervals within the stochastic sequence; and   selectively changing instances of one of the first and second inter-pulse intervals for the other thereof in order to weight the ratio of the number of the first inter-pulse intervals to the number of second inter-pulse intervals and thereby adjust the induced hearing percept.   
     
     
         3 . The method of  claim 1 , further comprising:
 receiving a sound signal;   wherein the sequence of electrical stimulation pulses is based on the sound signal.   
     
     
         4 . The method of  claim 1 , wherein:
 the sound signal includes at least a first pitch; and   the first inter-pulse interval is based at least on the first pitch.   
     
     
         5 . The method of  claim 4 , wherein:
 the second inter-pulse interval is based at least on a sequence of conditioning pulses.   
     
     
         6 . The method of  claim 4 , wherein:
 the sound signal includes at least a second pitch; and   the second inter-pulse interval is based at least on the second pitch.   
     
     
         7 . The method of  claim 1 , wherein:
 the first interval is substantially constant; and   the second interval is substantially constant.   
     
     
         8 . The method of  claim 1 , further comprising:
 delivering the stochastic sequence to the recipient via a single stimulation channel of the cochlear implant.   
     
     
         9 . A method for providing a hearing percept to a recipient of a cochlear implant comprising:
 generating a stochastic first sequence of electrical stimulation pulses having inter-pulse intervals distributed stochastically throughout the first sequence, at least some of the inter-pulse intervals being based on a second sequence of conditioning pulses.   
     
     
         10 . The method of  claim 9 , further comprising:
 encoding the second sequence of conditioning pulses within a third sequence of pulses representing at least a first pitch of a received sound signal to form the first sequence of electrical stimulation pulses.   
     
     
         11 . The method of  claim 10 , wherein:
 the inter-pulse intervals based on the second sequence of conditioning pulses are second inter-pulse intervals; and   the inter-pulse intervals further include:
 a first inter-pulse interval based on a pitch of the received sound signal. 
   
     
     
         12 . The method of  claim 9 , wherein the generating a stochastic first sequence includes at least one of:
 constraining the stochasticity of the first sequence of electrical stimulation pulses to be within controlled limits.   
     
     
         13 . The method of  claim 12 , wherein the constraining includes:
 limiting the number of consecutive instances of the same inter-pulse interval;   selectively changing instances of one of the first and second inter-pulse intervals for the other thereof in order to substantially balance the distribution of the first and second inter-pulse intervals within the stochastic first sequence; and   selectively changing instances of one of the first and second inter-pulse intervals for the other thereof in order to substantially balance the distribution of the first and second inter-pulse intervals within the stochastic first sequence.   
     
     
         14 . The method of  claim 9 , wherein:
 the inter-pulse intervals include at least first inter-pulse intervals and second inter-pulse intervals;   the first intervals are substantially constant; and   the second intervals are substantially constant.   
     
     
         15 . The method of  claim 9 , further comprising:
 receiving a sound signal;   wherein the first sequence of electrical stimulation pulses is based on the sound signal.   
     
     
         16 . The method of  claim 9 , further comprising:
 delivering the first sequence of electrical stimulation pulses to the recipient via a single stimulation channel of the cochlear implant.   
     
     
         17 . A hearing prosthesis for providing a hearing percept to a recipient of a cochlear implant, the prosthesis comprising:
 a sound pickup component configured to receive a sound signal having at least one pitch; and   a stochastic stimulation generator configured to generate a stochastic first sequence of electrical stimulation pulses based on the sound signal, inter-pulse intervals being distributed stochastically throughout the first sequence, at least some of the inter-pulse intervals being based on a second sequence of conditioning pulses.   
     
     
         18 . The prosthesis of  claim 17 , wherein:
 the stochastic stimulation generator is further configured to encode the second sequence of conditioning pulses within a third sequence of pulses representing at least a first pitch of a received sound signal to form the first sequence of electrical stimulation pulses.   
     
     
         19 . The prosthesis of  claim 18 , wherein:
 the inter-pulse intervals based on the second sequence of conditioning pulses are second inter-pulse intervals; and   the inter-pulse intervals further include:
 a first inter-pulse interval based on a pitch of the received sound signal. 
   
     
     
         20 . The prosthesis of  claim 17 , wherein:
 the stochastic stimulation generator is further configured to constrain the stochasticity of the first sequence of electrical stimulation pulses to be within controlled limit by doing at least one of:   limiting the number of consecutive instances of the same inter-pulse interval;   selectively changing instances of one of the first and second inter-pulse intervals for the other thereof in order to substantially balance the distribution of the first and second inter-pulse intervals within the stochastic first sequence; and   selectively changing instances of one of the first and second inter-pulse intervals for the other thereof in order to substantially balance the distribution of the first and second inter-pulse intervals within the stochastic first sequence.