# US 2010/0166238 A1 · Surround sound virtualization apparatus and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166238 A1 - Document ID: US20100166238A1 - Status: Published application - Kind: A1 - Application number: 12/458,028 - Filed: 2009-06-29 - Published: 2010-07-01 - Earliest claimed: 2008-12-29 - Assignees: Samsung Electronics Co., Ltd. - Inventors: Kang Eun Lee; Do-Hyung Kim; Chang Yong Son - Web page: https://patentgrep.com/patent/US20100166238A1 ## CPC - H04S 3/00: Systems employing more than two channels, e.g. quadraphonic (H04S5/00, H04S7/00 take precedence) - H04S: STEREOPHONIC SYSTEMS ## Abstract A surround sound virtualization apparatus and method. The surround sound virtualization apparatus may include an audio decoder to perform head-related transfer function (HRTF) filtering, and a time delay unit to provide a time delay to a plurality of output signals of the audio decoder. ## Claims ### Claim 1 A surround sound virtualization apparatus, comprising: an audio decoder to perform head-related transfer function (HRTF) filtering; and a time delay unit to provide a time delay to a plurality of output signals of the audio decoder. ### Claim 2 (depends on 1) The surround sound virtualization apparatus of claim 1, wherein the audio decoder comprises: a spectral decoding unit to extract a plurality of channel signals from an encoded bit stream; a surround virtualization unit to perform the HRTF filtering with respect to the plurality of extracted channel signals; and a domain transform unit to transform output signals of the surround virtualization unit into a time domain. ### Claim 3 (depends on 2) The surround sound virtualization apparatus of claim 2, wherein the surround virtualization unit performs the HRTF filtering in a frequency domain. ### Claim 4 (depends on 2) The surround sound virtualization apparatus of claim 2, wherein the surround virtualization unit multiplies the plurality of extracted channel signals with a plurality of response functions for applying an HRTF frequency characteristic. ### Claim 5 (depends on 2) The surround sound virtualization apparatus of claim 2, wherein, when a 5.1 channel sound is reproduced, the surround virtualization unit multiplies a front left channel signal with each of a first response function and a second response function to generate a first filter signal and a second filter signal, multiplies a surround left channel signal with each of a third response function and a fourth response function to generate a third filter signal and a fourth filter signal, multiplies a front right channel signal with each of a fifth response function and a sixth response function to generate a fifth filter signal and a sixth filter signal, multiplies a surround right channel signal with each of a seventh response function and an eighth response function to generate a seventh filter signal and an eighth filter signal, multiplies a center channel signal with a ninth response function to generate a ninth filter signal, and outputs the first filter signal, the second filter signal, the third filter signal, the fourth filter signal, the fifth filter signal, the sixth filter signal, the seventh filter signal, the eighth filter signal, the ninth filter signal, and a low frequency effect (LFE) channel signal. ### Claim 6 (depends on 5) The surround sound virtualization apparatus of claim 5, wherein the domain transform unit transforms each of the first filter signal, the second filter signal, the third filter signal, the fourth filter signal, the fifth filter signal, the sixth filter signal, the seventh filter signal, the eighth filter signal, the ninth filter signal, and the LFE channel signal into the time domain. ### Claim 7 (depends on 6) The surround sound virtualization apparatus of claim 6, wherein the time delay unit delays each of the first filter signal, the second filter signal, the third filter signal, the fourth filter signal, the fifth filter signal, the sixth filter signal, the seventh filter signal, the eighth filter signal, the ninth filter signal, and the LFE channel signal, transformed into the time domain, for a predetermined period of time, and outputs respective delayed signals. ### Claim 8 (depends on 2) The surround sound virtualization apparatus of claim 2, wherein the domain transform unit comprises: a signal addition unit to add all or a portion of the output signals of the surround virtualization unit into at least one added output signal; and an inverse transform unit to transform the at least one added output signal into the time domain. ### Claim 9 (depends on 1) The surround sound virtualization apparatus of claim 1, further comprising: a first adder to add a first group of output signals of the time delay unit; and a second adder to add a second group of output signals of the time delay unit. ### Claim 10 A surround sound virtualization method, comprising: extracting a plurality of channel signals from an encoded bit stream; performing HRTF filtering with respect to the plurality of extracted channel signals; transforming the plurality of filtered signals into a time domain; and providing a time delay to the plurality of signals transformed into the time domain. ### Claim 11 (depends on 10) The surround sound virtualization method of claim 10, wherein the performing of the HRTF filtering performs the HRTF filtering in a frequency domain. ### Claim 12 (depends on 10) The surround sound virtualization method of claim 10, wherein the performing of the HRTF filtering multiplies the plurality of extracted channel signals with a plurality of response functions for applying an HRTF frequency characteristic. ### Claim 13 (depends on 12) The surround sound virtualization method of claim 12, wherein, when a 5.1 channel sound is reproduced, the performing of the HRTF filtering comprises: multiplying a front left channel signal with each of a first response function and a second response function and generating a first filter signal and a second filter signal, multiplying a surround left channel signal with each of a third response function and a fourth response function and generating a third filter signal and a fourth filter signal, multiplying a front right channel signal with each of a fifth response function and a sixth response function and generating a fifth filter signal and a sixth filter signal, multiplying a surround right channel signal with each of a seventh response function and an eighth response function and generating a seventh filter signal and an eighth filter signal, multiplying a center channel signal with a ninth response function and generating a ninth filter signal; and outputting the first filter signal, the second filter signal, the third filter signal, the fourth filter signal, the fifth filter signal, the sixth filter signal, the seventh filter signal, the eighth filter signal, the ninth filter signal, and an LFE channel signal. ### Claim 14 (depends on 13) The surround sound virtualization method of claim 13, wherein the transforming transforms each of the first filter signal, the second filter signal, the third filter signal, the fourth filter signal, the fifth filter signal, the sixth filter signal, the seventh filter signal, the eighth filter signal, the ninth filter signal, and the LFE channel signal into the time domain. ### Claim 15 (depends on 10) The surround sound virtualization method of claim 10, wherein the transforming comprises: adding all or a portion of the plurality of filtered signals into at least one added signal; and transforming the at least one added signal into the time domain. ### Claim 16 (depends on 10) The surround sound virtualization method of claim 10, further comprising: adding a first group of output signals from among the plurality of signals where the time delay is provided; and adding a second group of output signals from among the plurality of signals where the time delay is provided. ### Claim 17 A computer-readable recording medium storing a program for causing a computer to implement a surround sound virtualization method, comprising: extracting a plurality of channel signals from an encoded bit stream; performing HRTF filtering with respect to the plurality of extracted channel signals; transforming the plurality of filtered signals into a time domain; and providing a time delay to the plurality of signals transformed into the time domain.