Directivity optimized sound reproduction

• US 10,368,183 B2
• Filed: 09/26/2014
• Issued: 07/30/2019
• Est. Priority Date: 05/19/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Holman, Tomlinson M.
• Primary Examiner(s): Monikang, George C
• Application Number:
  US15/311,828
• Publication Number:
  US 20170105084A1
• Time in Patent Office: 1,768 Days
• Field of Search: 381303, 381310, 381 58- 59
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 5/02 Spatial or constructional arrangements of loudspeakers
• CPC Class Codes: H04R 5/04 Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments combinations of amplifiers H03F3/68; stereophonic systems H04S
• 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 3/008 in which the audio signals are in digital form, i.e. employing more than two discrete digital channels data reduction aspects thereof based on psychoacoustics G10L19/02
• CPC Class Codes: H04S 7/302 Electronic adaptation of stereophonic sound system to listener position or orientation H04S7/301 takes precedence

Abstract

An audio system is described that receives a piece of sound program content for playback from a content distribution system. The piece of sound program content may include a multi-channel dialog signal and a combined multi-channel music and effects signal. The audio system may determine a first set of directivity patterns for the multi-channel dialog signal and a second set of directivity patterns for the combined multi-channel music and effects signal. The first set of directivity patterns associated with channels of the dialog signal may have higher directivity indexes than the second set of directivity patterns associated with corresponding channels of the music and effects signal. By associating dialog components with a higher directivity than music and effects components, the system increases the intelligibility of dialog for a piece of sound program content while allowing music and effects to retain conventional directivity having a typical ratio of direct-to-reverberant sound energy.

Claims

1. A method for playing a piece of sound program content, comprising:

receiving, from a server, a piece of sound program content and metadata, wherein the server a) combines a music signal with an effects signal to form a combined music and effects signal, resulting in a piece of sound program that includes a dialogue signal and a combined music and effects signal, b) determines a first directivity pattern for the dialogue signal of the piece of sound program content, the first directivity pattern characterized by a first directivity index, and c) determines a second directivity pattern for the combined music and effects signal of the piece of sound program content, the second directivity pattern characterized by a second directivity index, the second directivity index being less than the first directivity index, the first directivity pattern and second directivity pattern being included in the metadata; and

driving transducers in a speaker array in accordance with a first set of processed audio signals to produce sound of the dialogue signal having the first directivity pattern, and in accordance with a second set of processed audio signals to produce sound of the music and effects signal having the second directivity pattern.

2. The method of claim 1, wherein the first directivity pattern is determined for each channel of a multi-channel dialog stem in the piece of sound program content, and the second directivity pattern is determined for each channel of a combined music and effects stem in the piece of sound program content.

3. The method of claim 1, wherein the server is a remote content distribution server over a network connection.

4. The method of claim 1, wherein the first directivity index is based on a ratio of dialogue sound emitted at a target to dialogue sound emitted generally into a listening area, and the second directivity index is based on a ratio of music and effects sound emitted at the target to music and effects sound emitted generally into the listening area.

5. A server for processing a piece of sound program content, comprising:

a network interface of the server for receiving a multi-channel dialogue signal, a multi-channel music signal and a multi-channel effects signal for the piece of sound program content; and

a hardware processor of the server to;

combine a music signal with an effects signal to form a combined music and effects signal, determine a first directivity pattern for each channel of the multi-channel dialogue signal, the first directivity pattern characterized by a first directivity index, and determine a second directivity pattern for each channel of the combined multi-channel music and effects signal, the second directivity pattern characterized by a second directivity index, the second directivity index being less than the first directivity index, the first directivity pattern and second directivity pattern being included in metadata, wherein an audio receiver receives from the server a) the multi-channel dialogue signal, b) the combined multi-channel music and effects signal, and c) the metadata, and generates a first set of processed audio signals for transducers in a speaker array to produce sound of the dialogue signal having the first directivity pattern, and generates a second set of processed audio signals for the transducers in the speaker array to produce sound of the music and effects signal having the second directivity pattern.

6. An article of manufacture, comprising:

a non-transitory machine-readable storage medium that stores instructions which, when executed by a processor in a server, determine a first directivity pattern for each channel of a multi-channel dialogue signal for a piece of sound program content, the first directivity pattern characterized by a first directivity index;

determine a second directivity pattern for each channel of a combined multi-channel music and effects signal for the piece of sound program content, the second directivity pattern characterized by a second directivity index, the second directivity index being less than the first directivity index, the first directivity pattern and second directivity pattern being included in metadata;

transmitting, by the server to an audio receiver, a) the multi-channel dialogue signal, b) the combined multi-channel music and effects signal, and c) the metadata, wherein the audio receiver generates a first set of processed audio signals for the channels of the combined multi-channel dialogue signal for transducers in a speaker array to produce sound of the multi-channel dialogue signal having the first directivity pattern, and generates a second set of processed audio signals for the channels of the combined multi-channel music and effects signal for the transducers in the speaker array to produce sound of the combined multi-channel music and effects signal having the second directivity pattern.

7. The article of manufacture of claim 6, wherein the article of manufacture is a remote content distribution server, that transmits the multi-channel dialogue signal, the combined multi-channel music and effect signal, and the metadata, to the audio receiver, over a network connection.

8. The article of manufacture of claim 6, wherein the first directivity index is based on a ratio of dialogue sound emitted at a target to dialogue sound emitted generally into a listening area, and the second directivity index is based on a ratio of music and effects sound emitted at the target to music and effects sound emitted generally into the listening area.