Processing method for localization of acoustic image for audio signals for the left and right ears

• US 6,763,115 B1
• Filed: 07/26/1999
• Issued: 07/13/2004
• Est. Priority Date: 07/30/1998
• Status: Expired due to Fees

• Current Assignee: Arnis Sound Technologies Company Limited
• Original Assignee: A LIMITED RESPONSIBILITY COMPANY, RESEARCH NETWORK, Open Heart Ltd.
• Inventors: Kobayashi, Wataru
• Primary Examiner(s): Mei, Xu
• Application Number:
  US09/360,456
• Time in Patent Office: 1,814 Days
• Field of Search: 381/1, 381/17, 381/18, 381/19, 381/309, 381/310, 381/99, 381/74, 381/26
• US Class Current: 381/309
• CPC Class Codes: H04S 1/002 Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution control circuits for electronic adaptation of the sound field H04S7/30
• CPC Class Codes: H04S 1/005 For headphones

Abstract

In views of a disadvantage that in a conventional method for localization of sound image in stereo listening, the amount of software is increased and the scale of hardware is enlarged, this invention has been achieved to solve such a problem and intends to provide a processing method for audio signal to be inputted from an appropriate sound source capable of higher precision localization of sound image than the conventional method. When a sound generated from an appropriate sound source SS is processed as an audio signal in the order of inputs on time series, the inputted audio signal is transformed into audio signals for the left and right ears of a person and further each of the audio signals is divided to at least two frequency bands. Then, the divided audio signal of each band is subjected to a processing for controlling an element for a feeling of the direction of a sound source SS and an element for a feeling of the distance up to that sound source, which are appealed to person'"'"'s auditory sense and outputting the processed audio signal.

Claims

1. A processing method for localization of a sound image for audio signals for the left and right ears comprising, when a sound generated from an appropriate sound source is processed as an audio signal in the order of inputs on time series, the steps of:

transforming the inputted audio signal to audio signals for the left and right ears of a person;

dividing each of the audio signals into frequency bands selected from the group comprising;

a low/medium range and high range;

a low range and medium/high range; and

a low range, medium range and high range, wherein the low range band is a frequency band of less than aHz having a half wave length corresponding to a diameter of a head of a person, the high range band is a frequency band of more than bHz having a half wave length corresponding to a diameter of a concha of a person, and the medium range band is a frequency band between aHz and bHz; and

subjecting the divided audio signal of each band to a processing for controlling an element for a feeling of the direction of the sound source to be applied on a person'"'"'s auditory sense and an element for a feeling of the distance up to the sound source and outputting the processed audio signal.

2. A processing method for localization of a sound image for audio signals for the left and right ears according to claim 1 wherein the element for a feeling of the direction of the sound source to be controlled is a difference of time or a difference of sound volume with respect to the left and right ears of the audio signal or the difference of time and difference of sound volume.

3. A processing method for localization of a sound image for audio signals for the left and right ears according to claim 1 wherein the element for a feeling of the distance up to the sound source to be controlled is a difference of sound volume or a difference of time with respect to the left and right ears of the audio signal or the difference of sound volume and the difference of time.

4. A processing method for localization of a sound image for an audio signal for the left and right ears comprising the steps of:

dividing an audio acoustic signal inputted appropriately from a sound source to sounds for the left and right ears of a person;

dividing the audio inputted signal of each ear to such frequency bands as low/medium range and high range, low range and medium/high range or low range, medium range and high range; and

processing the audio signals for the left and right ears while the medium range band is subjected to a control based on a simulation by a head portion transmission function of a frequency characteristic, the low range band is subjected to a control with a difference of time or a difference of time and a difference of sound volume as parameters, and the high range band is subjected to a control with a difference of sound volume or a difference of sound volume and difference of time taken by combfilter processing as parameters.

5. A processing method for localization of a sound image for the audio signal for the left and right ears according to claim 4 wherein the medium range band is about 1,000-4,000 Hz.

6. A processing method for localization of a sound image for the audio signal for the left and right ears according to claim 4 wherein the low range band is a band of less than about 1,000 Hz.

7. A processing method for localization of a sound image for the audio signal for the left and right ears according to claim 4 wherein the high range band is a band of above about 4,000 Hz.