A Sound Processor for Cochlear Implant Using a Simple Dual Path Nonlinear Model of Basilar Membrane

Table 1

Center frequencies and bandwidths of the filter arrays used for frequency decomposition.

(a) 4 Channel implementation

	Ch. 1	Ch. 2	Ch. 3	Ch. 4
	CFs and BWs of BPFs (in conventional strategy)
CF (Hz)	460	953	1971	4078
BW (Hz)	321	664	1373	2426
	CFs and BWs of tip and tail BPFs (in proposed strategy)
CF (Hz)	460	953	1971	4078
BW of tip filter (Hz)	321	664	1373	2426
BW of tail filter (Hz)	107	221.3	457.7	808.7

(b) 8 Channel implementation

	Ch. 1	Ch. 2	Ch. 3	Ch. 4	Ch. 5	Ch. 6	Ch. 7	Ch. 8
	CFs and BWs of BPFs (in conventional strategy)
CF (Hz)	394	692	1064	1528	2109	2834	3740	4871
BW (Hz)	265	331	431	516	645	805	1006	1257
	CFs and BWs of tip and tail BPFs (in proposed strategy)
CF (Hz)	394	692	1064	1528	2109	2834	3740	4871
BW of tip filter (Hz)	265	331	431	516	645	805	1006	1257
BW of tail filter (Hz)	83.3	110.3	143.7	172	215	268.3	335.3	419

(c) 12 Channel implementation

	Ch. 1	Ch. 2	Ch. 3	Ch. 4	Ch. 5	Ch. 6	Ch. 7	Ch. 8	Ch. 9	Ch. 10	Ch. 11	Ch. 12
	CFs and BWs of BPFs (in conventional strategy)
CF (Hz)	274	453	662	905	1190	1521	1908	2359	2885	3499	4215	5050
BW (Hz)	165	193	225	262	306	357	416	486	567	661	771	900
	CFs and BWs of tip and tail BPFs (in proposed strategy)
CF (Hz)	274	453	662	905	1190	1521	1908	2359	2885	3499	4215	5050
BW of tip filter (Hz)	165	193	225	262	306	357	416	486	567	661	771	900
BW of tail filter (Hz)	55	64.3	75	87.3	102	119	138.7	162	189	220.3	257	300

CF: center frequency, BPF: bandpass filter, BW: bandwidth.