U.S. patent application number 11/845484 was filed with the patent office on 2009-03-05 for manipulating spatial processing in a audio system.
Invention is credited to Tobe Z. Barksdale, Shiufun Cheung, Ronald A. Fowler, Darby Edward Hadley, Ryo Maiguma, Takao Nakayama, Davis Y. Pan, Bruce C. Po, Katsumi Tomida, Petr Vicherek.
Application Number | 20090060208 11/845484 |
Document ID | / |
Family ID | 39790452 |
Filed Date | 2009-03-05 |
United States Patent
Application |
20090060208 |
Kind Code |
A1 |
Pan; Davis Y. ; et
al. |
March 5, 2009 |
Manipulating Spatial Processing in a Audio System
Abstract
A vehicle audio system that includes a source of audio signals,
which may include both entertainment audio signals and announcement
audio signals, speakers for radiating audio signals, and spatial
enhancement circuitry comprising circuitry to avoid applying
spatial enhancement processing to the announcement audio
signals.
Inventors: |
Pan; Davis Y.; (Arlington,
MA) ; Cheung; Shiufun; (Lexington, MA) ;
Hadley; Darby Edward; (Westborough, MA) ; Maiguma;
Ryo; (Tokyo, JP) ; Nakayama; Takao; (Tokyo,
JP) ; Po; Bruce C.; (Waltham, MA) ; Tomida;
Katsumi; (Kawasaki City, JP) ; Vicherek; Petr;
(Harvard, MA) ; Barksdale; Tobe Z.; (Bolton,
MA) ; Fowler; Ronald A.; (Westford, MA) |
Correspondence
Address: |
Bose Corporation;c/o Donna Griffiths
The Mountain, MS 40, IP Legal - Patent Support
Framingham
MA
01701
US
|
Family ID: |
39790452 |
Appl. No.: |
11/845484 |
Filed: |
August 27, 2007 |
Current U.S.
Class: |
381/17 ; 381/120;
381/77; 381/86 |
Current CPC
Class: |
H04R 2499/13 20130101;
H04S 7/30 20130101 |
Class at
Publication: |
381/17 ; 381/120;
381/77; 381/86 |
International
Class: |
H04R 5/00 20060101
H04R005/00; H03F 21/00 20060101 H03F021/00; H04B 1/00 20060101
H04B001/00 |
Claims
1. A vehicle audio system comprising: a source of audio signals,
which may include both entertainment audio signals and announcement
audio signals; speakers for radiating audio signals; and spatial
enhancement circuitry comprising circuitry to avoid applying
spatial enhancement processing to the announcement audio
signals.
2. A vehicle audio system according to claim 1, wherein the spatial
enhancement circuitry applies no spatial processing operations to
the audio signals received from the source if there is announcement
audio content in the audio signals received from the source.
3. A vehicle audio system according to claim 1, wherein the spatial
enhancement circuitry includes: first alternately selectable
circuitry for applying the spatial enhancement processing to the
audio signals; second alternately selectable circuitry for applying
no spatial enhancement processing to the audio signals; and
circuitry for selecting the audio signals from the first or second
alternately selectable circuitry based on the presence of
announcement audio signal in the combined audio signals.
4. A vehicle audio system according to claim 1, wherein the spatial
enhancement circuitry comprises circuitry for separating the audio
signals from the audio signal source into entertainment audio
signals and announcement audio signals; circuitry for applying
spatial enhancement processing to the entertainment audio signals;
and circuitry for combining the processed entertainment audio
signals and the announcement audio signals.
5. A vehicle audio system according to claim 1, wherein the source
of audio signals comprises a source of front audio signals that may
contain front announcement audio signals, hereinafter referred to
as front audio:signals, and a source of rear audio signals that may
contain rear announcement audio signals, hereinafter referred to as
rear audio signals, the audio system further comprising: front
spatial processing:circuitry comprising first alternately
selectable front circuitry for applying the spatial enhancement
processing to the front audio signals; second alternately
selectable front circuitry for applying no spatial enhancement
processing to the front audio signals; and circuitry for selecting
the audio signals from the first or second alternately selectable
front circuitry based on the presence of announcement audio signal
in the front audio signals, the audio system further comprising
rear spatial processing circuitry comprising first alternately
selectable rear circuitry for applying the spatial enhancement
processing to the rear audio signals; second alternately selectable
rear circuitry for applying no spatial enhancement processing to
the rear audio signals; and circuitry for selecting the audio
signals from the first or second alternately selectable circuitry
rear based on the presence of announcement audio signal in the rear
audio signals
6. A vehicle audio system according to claim 1, wherein the spatial
enhancement circuitry applies spatial enhancement processing to the
entertainment audio signals and does not apply spatial enhancement
processing to the announcement audio signals.
7. A method for operating a vehicle audio system comprising:
receiving audio signals that may contain announcement audio
signals; if the received audio signals do not contain announcement
audio signals, applying spatial processing to the received audio
signals; if the received audio signals include announcement audio
signals, not applying spatial processing to the announcement audio
signals.
8. A method according to claim 7, further comprising: if the
received audio signals include announcement audio signals and
entertainment audio signals, applying spatial processing to the
entertainment audio signals.
9. A vehicle audio amplifier comprising: an input terminal for
receiving audio signals that may include announcement audio
signals; and spatial enhancement circuitry containing circuitry to
avoid applying spatial enhancement processing to the announcement
audio signals.
10. A vehicle audio amplifier according to claim 9, wherein the
spatial enhancement circuitry applies no spatial processing
operations to the received audio signals if the received audio
signals include announcement audio signals.
11. A vehicle audio, amplifier according to claim 9, wherein the
spatial enhancement circuitry includes: first alternately
selectable circuitry for applying the spatial enhancement
processing to the combined audio signals; second alternately
selectable circuitry for applying no spatial enhancement processing
to the combined audio signals; and circuitry for selecting the
audio signals from the first or second alternately selectable
circuitry based on the presence of announcement audio signals in
the combined audio signals.
12. A vehicle audio amplifier according to claim 9, wherein the
spatial enhancement circuitry comprises circuitry for separating
the combined audio signals into entertainment audio signals and
announcement audio signals; circuitry for applying spatial
enhancement processing to the entertainment audio signals; and
circuitry for combining the processed entertainment audio signals
and the announcement audio signals.
13. A vehicle audio amplifier according to claim 9, the input
terminal comprising an input terminal for receiving front audio
signals that may include announcement audio signals, hereinafter
referred to as front input terminal and an input terminal for
receiving rear audio signals which may include announcement audio
signals, hereinafter referred to as rear input terminal, the
amplifier further comprising: front spatial processing circuitry
comprising first alternately selectable front circuitry for
applying the spatial enhancement processing to the front audio
signals; second alternately selectable front circuitry for applying
no spatial enhancement processing to the front audio signals; and
circuitry for selecting the audio signals from the first or second
alternately selectable front circuitry based on the presence of
announcement audio signal in the front audio signals, the audio
system further comprising rear spatial processing circuitry
comprising first alternately selectable rear circuitry for applying
the spatial enhancement processing to the rear audio signals;
second alternately rear selectable circuitry for applying no
spatial enhancement processing to the rear audio signals; and
circuitry for selecting the audio signals from the first or second
alternately selectable rear circuitry based on the presence of
announcement audio signal in the rear audio signals.
Description
BACKGROUND
[0001] This disclosure relates to manipulating spatial processing
in a vehicle audio system that is used to radiate entertainment
audio and announcement audio.
SUMMARY
[0002] In one aspect, a vehicle audio system includes a source of
audio signals, which may include both entertainment audio signals
and announcement audio signals, speakers for radiating audio
signals, and spatial enhancement circuitry comprising circuitry to
avoid applying spatial enhancement processing to the announcement
audio signals. The spatial enhancement circuitry may apply no
spatial processing operations to the audio signals received from
the source if there is announcement audio content in the audio
signals received from the source. The spatial enhancement circuitry
may include first alternately selectable circuitry for applying the
spatial enhancement processing to the audio signals, second
alternately selectable circuitry for applying no spatial
enhancement processing to the audio signals, and circuitry for
selecting the audio signals from the first or second alternately
selectable circuitry based on the presence of announcement audio
signal in the combined audio signals. The spatial enhancement
circuitry may include circuitry for separating the audio signals
from the audio signal source into entertainment audio signals and
announcement audio signals, circuitry for applying spatial
enhancement processing to the entertainment audio signals, and
circuitry for combining the processed entertainment audio signals
and the announcement audio signals. The source of audio signals may
include a source of front audio signals that may contain front
announcement audio signals, hereinafter referred to as front audio
signals, and a source of rear audio signals that may contain rear
announcement audio signals, hereinafter referred to as rear audio
signals and the audio system may further include front spatial
processing circuitry including first alternately selectable front
circuitry for applying the spatial enhancement processing to the
front audio signals, second alternately selectable front circuitry
for applying no spatial enhancement processing to the front audio
signals, and circuitry for selecting the audio signals from the
first or second alternately selectable front circuitry based on the
presence of announcement audio signal in the front audio signals.
The audio may further include rear spatial processing circuitry
that includes first alternately selectable rear circuitry for
applying the spatial enhancement processing to the rear audio
signals, second alternately selectable rear circuitry for applying
no spatial enhancement processing to the rear audio signals, and
circuitry for selecting the audio signals from the first or second
alternately selectable circuitry rear based on the presence of
announcement audio signal in the rear audio signals. The spatial
enhancement circuitry may apply spatial enhancement processing to
the entertainment audio signals and not apply spatial enhancement
processing to the announcement audio signals.
[0003] In another aspect, a method for operating a vehicle audio
system includes receiving audio signals that may contain
announcement audio signals; if the received audio signals do not
contain announcement audio signals, the method includes applying
spatial processing to the received audio signals; and if the
received audio signals include announcement audio signals, the
method does not apply spatial processing to the announcement audio
signals. The method may include, if the received audio signals
include announcement audio signals and entertainment audio signals,
applying spatial processing to the entertainment audio signals.
[0004] In another aspect, a vehicle audio amplifier includes an
input terminal for receiving audio signals that may include
announcement audio signals and spatial enhancement circuitry
containing circuitry to avoid applying spatial enhancement
processing to the announcement audio signals. The spatial
enhancement circuitry may apply no spatial processing operations to
the received audio signals if the received audio signals include
announcement audio signals. The spatial enhancement circuitry may
include first alternately selectable circuitry for applying the
spatial enhancement processing to the combined audio signals,
second alternately selectable circuitry for applying no spatial
enhancement processing to the combined audio signals; and circuitry
for selecting the audio signals from the first or second
alternately selectable circuitry based on the presence of
announcement audio signals in the combined audio signals. The
spatial enhancement circuitry may include circuitry for separating
the combined audio signals into entertainment audio signals and
announcement audio signals, circuitry for applying spatial
enhancement processing to the entertainment audio signals, and
circuitry for combining the processed entertainment audio signals
and the announcement audio signals. The input terminal may include
an input terminal for receiving front audio signals that may
include announcement audio signals, hereinafter referred to as
front input terminal and an input terminal for receiving rear audio
signals which may include announcement audio signals, hereinafter
referred to as rear input terminal. The amplifier may further
include front spatial processing circuitry including first
alternately selectable front circuitry for applying the spatial
enhancement processing to the front audio signals, second
alternately selectable front circuitry for applying no spatial
enhancement processing to the front audio signals, and circuitry
for selecting the audio signals from the first or second
alternately selectable front circuitry based on the presence of
announcement audio signal in the front audio signals, and the audio
system may further include rear spatial processing circuitry
including first alternately selectable rear circuitry for applying
the spatial enhancement processing to the rear audio signals,
second alternately rear selectable circuitry for applying no
spatial enhancement processing to the rear audio signals, and
circuitry for selecting the audio signals from the first or second
alternately selectable rear circuitry based on the presence of
announcement audio signal in the rear audio signals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a block diagram of a vehicle with an audio
system;
[0006] FIG. 2 is a block diagram of elements of the audio system in
bypass mode;
[0007] FIG. 3 is a block diagram of elements of the audio system in
extraction mode; and
[0008] FIG. 4 is a block diagram of elements of an audio system
with two spatial processing paths
DETAILED DESCRIPTION
[0009] Referring to FIG. 1, a vehicle audio system 100 includes a
head unit 120 coupled to an amplifier 140 through an amplifier
input terminal 380. The amplifier 340 is in turn coupled to
speakers 302, 303, 304, 306, and 308 through output terminals such
a terminal 390. In this particular example, the head unit 120
provides a user with AM/FM tuning, and CD playback capability. The
head unit 120 also is able to receive audio signals from external
sources 125a, 125b providing audio to a vehicle listening space.
The external audio sources may include digital music players (i.e.
mp3, CD, DVD) 125a, portable navigation device 126b, satellite
radio receiver, and/or other sources. In addition to entertainment
audio, the head unit 100 provides non-entertainment, announcement
audio. Announcement audio may include navigation system audio
instructions, vehicle chimes, enunciated announcements, cell phone
chimes/rings, cell phone conversation, and other non-entertainment
audio sources.
[0010] The head unit 120 provides to amplifier 140 both the
entertainment audio and announcement audio when present. The
amplifier 140 include circuitry for applying spatial enhancement
processing to the audio signal to enhance the presentation of
entertainment audio inside the vehicle cabin. Spatial enhancement
can include adding channels, such as center or surround channels,
or other processing that can affect the spatial characteristics of
the audio system, for example by "widening" the sound stage by
modifying inter-aural crosstalk.
[0011] When announcement audio is present in a combined audio
signal, spatially enhancing the combined entertainment and
announcement audio signal can lead to undesirable audible
artifacts. For example, the resulting audio presentation may
include distorted sound, or bleeding of the announcement audio into
entertainment audio. Similarly, the spatial enhancement processing
could direct the pertinent audio signal so that the perceived
source is in an illogical direction in relation to a listener's
location.
[0012] In one particular example, a vehicle chime for reminding the
car's occupants to fasten their seatbelt may sound as if it comes
from the rear of the vehicle if certain spatial enhancement
processing is applied to the signal. If this chime comes from the
rear instead of the dashboard, occupants may be confused as to the
meaning of the clime because most people are accustomed to
warning/reminder chimes coming from the dashboard area of the
vehicle. Misdirected signaling can be particularly concerning when
audio signal is intended as a reminder or warning for the driver of
a vehicle.
[0013] To reduce such audible artifacts the amplifier 140 contains
circuitry that avoids applying to the spatial processing operations
to announcement audio.
[0014] The head unit 120 also includes fader controls (not shown)
that permit a user to control the relative volume between the front
(302, 303, 304) and rear speakers (306, 308). For example, the user
can manipulate the fader control to direct audio to be faded to the
rear speakers only. However, in some implementations, the amplifier
140 directs announcement audio to the appropriate speaker to
maintain the intended location of the announcement audio despite
the fader setting. For example, if a a DVD movie is playing for
children in the rear seat, a parent may fade adjust the fade
control so that the entertainment audio is directed completely to
rear speakers (306, 308). However if a cellular phone connected to
(or integrated within) the entertainment system 100 sends a ring
chime signal to the amplifier 340, the amplifier 340 will present
the ring chime in one or more of the front speakers (e.g., speaker
302, 303 and/or 304).
[0015] The processing of announcement audio can be done in at least
two ways: a bypass mode and an extraction mode.
[0016] For example, as shown in FIG. 2 an amplifier 140' in bypass
mode includes two branches, 320a, b. An audio signal received from
the head unit 120 is processed in parallel in both branches. Branch
320a applies spatial processing (e.g., spatial processing described
in U.S. Pat. No. 7,016,501) and branch 320b applies no spatial
processing. A crossfader 330 is coupled to both branches and
selects audio from branch 320a or 320b based on an indication from
a control signal from the head unit 120 on control signal line 370
as to the presence (or absence) of announcement audio.
[0017] The crossfader 330 also may process the selected signal so
that transition from selection of one branch to another is smooth.
The output matrixer then directs the audio signals to the
appropriate speakers.
[0018] As shown in FIG. 3, an amplifier 140'' in extraction mode
includes an announcement audio extractor 310 that extracts
announcement audio from the signal received from the head unit. The
remainder of the original signal (that is, the entertainment audio
signal) is processed by spatial processor 360. The announcement
audio is then summed back into the spatially processed
entertainment audio signals at output matrixer 350. Audio signals
are then directed to the associated speakers. In some
implementations, the announcement audio is directed to associated
speakers downstream from the application of fader settings, so that
announcement audio is radiated properly irrespective of fader
settings. In extraction mode, the speakers 302, 303, 304, 306, and
308 simultaneously radiate the spatially processed entertainment
signals and the non-spatially processed announcement audio signals
or radiate the spatially processed entertainment audio signals.
[0019] In systems in which the head unit transmits a front audio
signal and a rear audio signal and inserts announcement audio in
the front audio signal only, the announcement audio extractor 310
may compare the front audio signal and the rear audio signal and
extract the difference between the front audio signal and the rear
audio signal to determine the announcement audio content.
[0020] Referring to FIG. 4, a head unit 120' is coupled to two
processing paths that are each similar to the processing path
illustrated in FIG. 2. A front audio signal (i.e., the audio
signals intended for speakers located in the front portion of the
automobile's cabin) is processed separately from the rear audio
signal (i.e., the audio signals intended for speakers located in
the rear portion of the cabin). Each path includes a separately
controlled crossfader (360R, 360F) so that, for example, the front
crossfader 360F can select the spatially processed signal from
signal path 320a-F based on the absence of announcement audio as
indicated by the absence of an indication on front control line
370F. Similarly, the rear crossfader 360R could select the bypassed
signal from signal path 320b-R based on the presence of
announcement audio as indicated by the presence of an indication on
control line 370R. An amplifier that contains two implementations
of the spatial pathway permits announcement audio to be separately
radiated by both front and rear speakers, with less likelihood of
misdirection. The use of multiple pathways permits greater
flexibility in system design and allows for more announcement audio
radiation source points. For example, some automobile warning
systems have sensors that detect if there is an object near the
rear of the automobile if the automobile is in reverse gear. The
warning noise can come from one or both of the rear speakers,
providing an audible cue of the presence of the object near the
rear of the automobile.
[0021] Though the elements of several views of the drawing may be
shown and described as discrete elements in a block diagram and may
be referred to as "circuitry", unless otherwise indicated, the
elements may be implemented as one of, or a combination of, analog
circuitry, digital circuitry, or one or more microprocessors
executing software instructions. The software instructions may
include digital signal processing (DSP) instructions. Unless
otherwise indicated, signal lines and terminals may be implemented
as discrete analog or digital signal lines or terminals, as a
single discrete digital signal line or terminal with appropriate
signal processing to process separate streams of audio signals, or
as elements of a wireless communication system. Some of the
processing operations maybe expressed in terms of the calculation
and application of coefficients. The equivalent of calculating and
applying coefficients can be performed by other analog or digital
signal processing techniques and are included within the scope of
this patent application. Unless otherwise indicated, audio signals
or video signals or both may be encoded and transmitted in either
digital or analog form; conventional digital-to-analog or
analog-to-digital converters nay be omitted in some figures. Audio
signal processing (for example equalization) that does not
significantly affect the spatial characteristics of the audio is
omitted from the figures. For simplicity of wording "radiating
acoustic energy corresponding to entertainment audio signals" may
be referred to as "radiating entertainment audio signals", and
"radiating acoustic energy corresponding to announcement audio
signals may be referred to as "radiating announcement audio
signals."
[0022] A number of embodiments of the invention have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. Accordingly, other embodiments are within
the scope of the following claims.
* * * * *