Crosstalk cancellation system with sound quality preservation and parameter determining method thereof

Abstract

A crosstalk cancellation system for preserving quality of sound and the parameter determining method thereof. The system can cancel a two-channel audio signal without compensating a frequency response of an ipsilateral HRTF. The method includes providing an audio signal input device for inputting the two-channel audio signal, modeling a relation between parameters of the crosstalk cancellation system and a head related transfer function (HRTF) to thereby obtain an output transfer impulse response, setting contralateral parts of the output transfer impulse response approximate to zero, setting ipsilateral parts of the output transfer impulse response equal to a delay of ipsilateral head related impulse responses (HRIRs) corresponding to the HRTF, and performing an inverse operation to compute the parameters of the crosstalk cancellation system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a 3D sound reproduction over two channel speakers in the prior art;

FIG. 2 is a schematic view of an application with a crosstalk cancellation system with sound quality preservation in accordance with the invention;

FIG. 3 is a flowchart of a parameter determining method for a crosstalk cancellation system with sound quality preservation in accordance with the invention;

FIG. 4 is a flowchart of another parameter determining method for a crosstalk cancellation system with sound quality preservation in accordance with the invention;

FIG. 5 is a schematic graph of the impulse responses of ipsilateral and contralateral crosstalk cancellation filters in the prior art;

FIG. 6 is a comparative graph of the frequency responses, before and after the processing of ipsilateral and contralateral crosstalk cancellation system in the prior art;

FIG. 7 is a schematic graph of the impulse responses of ipsilateral and contralateral crosstalk cancellation filters in accordance with an embodiment of the invention;

FIG. 8 is a comparative graph of the field frequency responses, before and after the processing of ipsilateral and contralateral crosstalk cancellation system in accordance with an embodiment of the invention;

FIG. 9 is a schematic graph of the impulse responses of ipsilateral and contralateral crosstalk cancellation filters in accordance with another embodiment of the invention; and

FIG. 10 is a comparative graph of the field frequency responses, before and after the processing of ipsilateral and contralateral crosstalk cancellation system in accordance with another embodiment of the invention.

Claims

1. A parameter determining method applied to a crosstalk cancellation system for preserving quality of sound, the method comprising the steps of: (A) providing an audio signal input device for inputting a two-channel audio signal;(B) modeling a relation between parameters of the crosstalk cancellation system and a head related transfer function (HRTF) to thereby obtain an output transfer impulse response;(C) setting contralateral parts of the output transfer impulse response approximate to zero;(D) setting ipsilateral parts of the output transfer impulse response equal to a delay of ipsilateral head related impulse responses (HRIRs) corresponding to the HRTF; and(E) performing an inverse operation to compute the parameters of the crosstalk cancellation system.

2. The method as claimed in claim 1, wherein in step (B) the relation between the parameters of the crosstalk cancellation system and the head related transfer function (HRTF) is expressed by

3. The method as claimed in claim 2, wherein the step (C) of setting contralateral parts of the output transfer impulse response approximate to zero is expressed by d12(n)=γ,d21(n)=γ,

4. The method as claimed in claim 3, wherein the step (D) of setting ipsilateral parts of the output transfer impulse response equal to a delay of ipsilateral head related impulse responses (HRIRs) corresponding to the HRTF is expressed by d11(n)=δ(n−Δ){circle around (×)}h11(n),d22(n)=δ(n−Δ){circle around (×)}h22(n),

5. The method as claimed in claim 4, wherein in step (E) the inverse operation is performed on the following equation:

6. The method as claimed in claim 5, wherein the step (D) sets the ipsilateral parts of the output transfer impulse response without compensating a frequency response of an ipsilateral HRTF.

7. A parameter determining method applied to a crosstalk cancellation system for preserving quality of sound, the method comprising the steps of: (A) providing an audio signal input device for inputting a two-channel audio signal;(B) modeling a relation between parameters of the crosstalk cancellation system and a head related transfer function (HRTF) to thereby obtain an output transfer impulse response;(C) setting contralateral parts of the output transfer impulse response approximate to zero;(D) setting ipsilateral impulse parameters of the crosstalk cancellation system for preserving quality of sound equal to a delayed impulse function; and(E) performing an inverse operation to compute the parameters of the crosstalk cancellation system.

8. The method as claimed in claim 7, wherein in step (B) the relation between the parameters of the crosstalk cancellation system and the head related transfer function (HRTF) is expressed by:

9. The method as claimed in claim 8, wherein the step (C) of setting contralateral parts of the output transfer impulse response approximate to zero is expressed by d12(n)=γ,d21(n)=γ,

10. The method as claimed in claim 9, wherein the step (D) of setting ipsilateral parts of the output transfer impulse response equal to a delay of ipsilateral head related impulse responses (HRIRs) corresponding to the HRTF is expressed by c11(n)=δ(n−Δ),c22(n)=δ(n−Δ),

11. The method as claimed in claim 10, wherein in step (E) the inverse operation is performed on the following equation:

12. The method as claimed in claim 11, wherein the step (D) sets the ipsilateral parts of the output transfer impulse response without compensating a frequency response of an ipsilateral HRTF.

13. A crosstalk cancellation system with sound quality preservation, the crosstalk cancellation system comprising: a first ipsilateral head filter, connected to a left channel part of the two-channel audio signal, for passing through the left channel audio signal and producing a first ipsilateral head filter signal;a second ipsilateral head filter, connected to a right channel part of the two-channel audio signal, for passing through the right channel audio signal and producing a second ipsilateral head filter signal;a first contralateral head filter, connected to the left channel part of the two-channel audio signal, for canceling a first contralateral crosstalk of the left channel audio signal and producing a first contralateral head filter signal;a second contralateral head filter, connected to the right channel part of the two-channel audio signal, for canceling a second contralateral crosstalk of the right channel audio signal and producing a second contralateral head filter signal;a first adder, connected to the first ipsilateral head filter and the second contralateral head filter, for adding the first ipsilateral head filter signal and the second contralateral head filter signal to thereby produce a left channel output signal; anda second adder, connected to the second ipsilateral head filter and the first contralateral head filter, for adding the second ipsilateral head filter signal and the first contralateral head filter signal to thereby produce a right channel output signal;wherein the first ipsilateral head filter, the second ipsilateral head filter, the first contralateral head filter and the second contralateral head filter have parameters C11, C22, C21 and C12 respectively, and

14. A crosstalk cancellation system with sound quality preservation, the crosstalk cancellation system comprising: a first ipsilateral head filter, connected to a left channel part of the two-channel audio signal, for passing through the left channel audio signal and producing a first ipsilateral head filter signal;a second ipsilateral head filter, connected to a right channel part of the two-channel audio signal, for passing through the right channel audio signal and producing a second ipsilateral head filter signal;a first contralateral head filter, connected to the left channel part of the two-channel audio signal, for canceling a first contralateral crosstalk of the left channel audio signal and producing a first contralateral head filter signal;a second contralateral head filter, connected to the right channel part of the two-channel audio signal, for canceling a second contralateral crosstalk of the right channel audio signal and producing a second contralateral head filter signal;a first adder, connected to the first ipsilateral head filter and the second contralateral head filter, for adding the first ipsilateral head filter signal and the second contralateral head filter signal to thereby produce a left channel output signal; anda second adder, connected to the second ipsilateral head filter and the first contralateral head filter, for adding the second ipsilateral head filter signal and the first contralateral head filter signal to thereby produce a right channel output signal;wherein the first ipsilateral head filter, the second ipsilateral head filter, the first contralateral head filter and the second contralateral head filter have parameters C11, C22, C21 and C12 respectively, and −z−Δ{tilde over (H)}12={tilde over (H)}11C12,−z−Δ{tilde over (H)}21={tilde over (H)}22C21