Personal sound system with virtually positioned lateral speakers

• US 5,459,790 A
• Filed: 03/08/1994
• Issued: 10/17/1995
• Est. Priority Date: 03/08/1994
• Status: Expired due to Term

• Current Assignee: IMAX Corporation
• Original Assignee: Sonics Associates, Incorporated (IMAX Corporation)
• Inventors: Saunders, Stevan O., Scofield, William C.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): HARVEY, MINSUN OH
• Application Number:
  US08/208,336
• Time in Patent Office: 588 Days
• Field of Search: 381/1, 381/17, 381/18, 381/24, 381/25, 381/27, 381/86
• US Class Current: 381/310
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 5/033 Headphones for stereophonic communication details thereof, e.g. relating to batteries, cables or control elements H04R1/10
• CPC Class Codes: H04S 2400/01 Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved
• CPC Class Codes: H04S 3/00 Systems employing more than two channels, e.g. quadraphonic H04S5/00, H04S7/00 take precedence
• CPC Class Codes: H04S 3/004 For headphones
• CPC Class Codes: H04S 5/00 Pseudo-stereo systems, e.g. in which additional channel signals are derived from monophonic signals by means of phase shifting, time delay or reverberation
• CPC Class Codes: H04S 7/30 Control circuits for electronic adaptation of the sound field

Abstract

A head mounted surround sound virtual positioning system that includes a video recorder (200), which is operable to have disposed therein a tape (202), having a surround sound audio track associated therewith. The surround sound system is encoded on two channels, which are output to a Dolby® decoder (204), which is operable to extract the five surround sound system channels therefrom. The left front, left rear, right front and right rear channels are input to a virtual positioning system (264), which is operable to virtually position each of the speakers relative to the head of the listener (26). These signals are then combined with a combining circuit (268) to provide the virtual positioning of only two speaker lines (58) and (60), disposed adjacent the right and left ears of the listener (26). The speakers (58) and (60) are disposed on the head mounted system such that they are fixed relative to the ear of the listener and slightly forward of the ears and adjacent the head. The center speaker signal output of the decoder (204 ) is output from a separate external speaker (310). To provide a panning effect, a listener (330) can be disposed relative to a center speaker (336) and allowed to focus thereon. Two external speakers, a left external speaker (332) and a right external speaker (334) are virtually positioned to drive the binaural speakers (58) and (60). The listener (330) then focuses onto the center speaker (336) and the sound source is effectively fixed relative to the listener (330), such that any sound effects provided by the intended position of the speakers (332) and (334) are retained in the aural program that is virtually positioned relative to the listener (330).

Claims

1. A method for providing sound effects to a listener, comprising the steps of:

providing an external central speaker;

providing a sound source having at least three channels of sound, a first and central sound channel designed for driving an external central speaker, a second sound channel for being disposed at the leg of the listener designed to be output from an external left speaker disposed a predetermined distance from the listener and a third sound channel designed to be output from an external right speaker disposed a predetermined distance from the listener, the sound source representing an aural program that is designed for the listener to be in a predetermined sweet spot relative to the external central speaker, the designed for external right speaker and the designed for external left speaker;

driving the external central speaker with the sound signal from the first central sound channel, the external central speaker proportional relative to the listener;

disposing left and right binaural speakers proximate to the left and right earl, respectively, of the listener;

virtually positioning the second sound channel to the intended position of the designed for external left speaker relative to the sweet spot by generating a binaural signal and driving the left and right binaural speakers therewith; and

virtually positioning the third sound channel to the intended position of the designed for external right speaker relative to the sweet spot by generating a binaural signal and driving the left and right binaural speakers therewith.

2. The method of claim 1, wherein the step of disposing the left and right binaural speakers proximate to the left and right ear, respectively, of the listener, comprises fixedly disposing the left and right binaural speakers proximate to the left and right ears, respectively, of the listener, such that, when the listener moves his head, the left and right binaural speakers move accordingly.

3. The method of claim 1, and further comprising, a video program associated with the aural program that is disposed proximate to the external central speaker.

4. The method of claim 1, and further comprising, focusing by the listener to the central speaker when listening to the sound output by the external central speaker and the left and right binaural speakers.

5. The method of claim 1, wherein the step of disposing the right binaural speaker proximate to the right ear of the listener and the left binaural speaker proximate to the left ear of the listener comprises:

disposing a head mounted bracket on the head of a listener;

mounting the right binaural speaker on the bracket proximate to the right ear of the listener and then directed rearward to the right ear of the listener; and

mounting the left binaural speaker on the bracket proximate to the left ear of the listener and then directed rearward toward the left ear of the listener.

6. The method of claim 1, and further comprising, processing the virtually positioned second and third channels to account for the acoustics of an ideal theater, such that the listener receives the benefits of being in a virtual ideal theater.

7. The method of claim 6, wherein the step of processing comprises the step of processing the second and third channels with an algorithm that performs a real-time convolution of the impulse response of a given environment associated with the ideal theater with the virtually positioned second and third channels.