Apparatus and a method for manipulating an input audio signal

Patent metadata

Field	Value
Publication number	US-10178491-B2
Application number	US-201715411859-A
Country	US
Kind code	B2
Filing date	Jan 20, 2017
Priority date	Jul 22, 2014
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

The disclosure relates to an apparatus for manipulating an input audio signal associated to a spatial audio source within a spatial audio scenario, wherein the spatial audio source has a certain distance to a listener within the spatial audio scenario. The apparatus comprises an exciter adapted to manipulate the input audio signal to obtain an output audio signal, and a controller adapted to control parameters of the exciter for manipulating the input audio signal based on the certain distance.

First claim

What is claimed is:

1. An apparatus for manipulating an input audio signal, the apparatus comprising:
an exciter adapted to manipulate the input audio signal to obtain an output audio signal, wherein the input audio signal is associated with a spatial audio source, and the spatial audio source is separated from a listener by a first distance, wherein a non-linear processor of the exciter is adapted to limit a magnitude of a filtered audio signal in time domain to a magnitude less than a limiting threshold value to obtain a non-linearly processed audio signal; and
a controller adapted to control parameters of the exciter for manipulating the input audio signal based on the first distance, wherein the controller is adapted to control the limiting threshold value based on the first distance.

2. The apparatus of claim 1 , wherein the exciter comprises:
a band-pass filter adapted to filter the input audio signal to obtain a filtered audio signal;
a non-linear processor adapted to non-linearly process the filtered audio signal to obtain a non-linearly processed audio signal; and
a combiner adapted to combine the non-linearly processed audio signal with the input audio signal to obtain the output audio signal.

3. The apparatus of claim 1 , wherein the controller is adapted to determine a frequency transfer function of a band-pass filter of the exciter based on the first distance.

4. The apparatus of claim 1 , wherein the controller is adapted to:
increase at least one of a lower cut-off frequency and a higher cut-off frequency of a band-pass filter of the exciter based on a decrease in the first distance, and
decrease at least one of the lower cut-off frequency and the higher cut-off frequency of the band-pass filter of the exciter based on an increase in the first distance.

5. The apparatus of claim 1 , wherein the controller is adapted to:
increase a bandwidth of a band-pass filter of the exciter based on a decrease in the first distance, and
decrease the bandwidth of the band-pass filter of the exciter based on an increase in the first distance.

6. The apparatus of claim 1 , wherein the controller is adapted to determine at least one of a lower cut-off frequency and a higher cut-off frequency of a band-pass filter of the exciter according to the following equations:

f
H

=

(

2
-

r
norm

)

·

b

1
⁢

⁢
_
⁢

⁢
freq

f
L

=

(

2
-

r
norm

)

·

b

2
⁢

⁢
_
⁢

⁢
freq

r
norm

=

r

r

ma
⁢

⁢
x

wherein f H denotes the higher cut-off frequency, f L denotes the lower cut-off frequency, b 1 13 freq denotes a first reference cut-off frequency, b 2 _ freq denotes a second reference cut-off frequency, r denotes the first distance, r max denotes a maximum distance, and r norm denotes a normalized distance.

7. The apparatus of claim 1 , wherein the controller is adapted to control parameters of a non-linear processor of the exciter for obtaining a non-linearly processed audio signal based on the first distance.

8. The apparatus of claim 1 , wherein the controller is adapted to control parameters of a non-linear processor of the exciter, such that a non-linearly processed audio signal comprises:
at least one of more harmonics and more power in a high-frequency portion of the non-linearly processed audio signal in case of a decrease in the first distance, and
at least one of less harmonics and less power in the high-frequency portion of the non-linearly processed audio signal in case of an increase in the first distance.

9. The apparatus of claim 1 , wherein the controller is adapted to:
decrease the limiting threshold value based on a decrease in the first distance, and
increase the limiting threshold value based on an increase in the first distance.

10. The apparatus of claim 1 , wherein the controller is adapted to determine the limiting threshold value according to the following equations:

lt
=

LT
·

r
norm

r
norm

=

r

r
max

wherein lt denotes the limiting threshold value, LT denotes a limiting threshold constant, r denotes the first distance, r max denotes a maximum distance, and r norm denotes a normalized distance.

11. The apparatus of claim 1 , wherein a non-linear processor of the exciter is adapted to multiply a filtered audio signal by a gain signal in time domain, and wherein the gain signal is determined from the input audio signal based on the first distance.

12. The apparatus of claim 11 , wherein the controller is adapted to determine the gain signal based on the first distance according to the following equations:

μ
⁡

[
n
]

=

min
⁡

(

s
rms

Assignees

• Huawei Tech Co Ltd

Inventors

• Faller Christof
• Favrot Alexis
• Pang Liyun
• Grosche Peter
• Lang Yue

Classifications

• H04S3/008

  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 title

• H04S7/302 Primary

  Electronic adaptation of stereophonic sound system to listener position or orientation (H04S7/301 takes precedence) · CPC title

• H04R3/04

  for correcting frequency response · CPC title

• H04S2400/11

  Positioning of individual sound objects, e.g. moving airplane, within a sound field (H04S2420/13 takes precedence) · CPC title

• H04S2400/01

  Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved · CPC title