# US 2026/0101151 A1 · Audio signal processor

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2026/0101151 A1
- Document ID: US20260101151A1
- Status: Published application
- Kind: A1
- Application number: 19/348,138
- Filed: 2025-10-02
- Published: 2026-04-09
- Earliest claimed: 2024-10-09
- Assignees: Alps Alpine Co., Ltd.
- Applicants: Alps Alpine Co., Ltd.
- Inventors: Kazumasa NIHIRA; Keita TANNO
- Web page: https://patentgrep.com/patent/US20260101151A1

## CPC

- H04S 7/307: {Frequency adjustment, e.g. tone control (H04S7/301 takes precedence)}
- H04S 1/007: {in which the audio signals are in digital form (data reduction aspects thereof based on psychoacoustics G10L19/02)}
- H04S 7/302: {Electronic adaptation of stereophonic sound system to listener position or orientation (H04S7/301 takes precedence)}
- H04S 2400/11: Positioning of individual sound objects, e.g. moving airplane, within a sound field (H04S2420/13 takes precedence)
- H04S 2420/01: Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD]
- H04S: STEREOPHONIC SYSTEMS

## Abstract

An audio signal processor includes a harmonic signal generator to generate a harmonic signal that includes a signal generated by frequency scaling components of a target audio signal by a factor of k, a left audio signal generator to generate a left audio signal by convolving a head-related transfer function from a target localization position of the target audio signal to a left ear of a listener with the target audio signal, a right audio signal generator to generate a right audio signal by convolving a head-related transfer function from the target localization position to a right ear of the listener with the target audio signal, a left synthesizer to generate a left channel audio signal by synthesizing the left audio signal and the harmonic signal, and a right synthesizer to generate a right channel audio signal by synthesizing the right audio signal and the harmonic signal.

## Claims

### Claim 1

An audio signal processor comprising:
a harmonic signal generator configured to generate a harmonic signal that includes a signal generated by frequency scaling components of a target audio signal by a factor of k (k is an integer equal to or more than 2), the target audio signal being an audio signal to be processed;
a left audio signal generator configured to generate a left audio signal by convolving a head-related transfer function from a target localization position of the target audio signal to a left ear of a listener with the target audio signal;
a right audio signal generator configured to generate a right audio signal by convolving a head-related transfer function from the target localization position to a right ear of the listener with the target audio signal;
a left synthesizer configured to generate a left channel audio signal by synthesizing the left audio signal and the harmonic signal; and
a right synthesizer configured to generate a right channel audio signal by synthesizing the right audio signal and the harmonic signal.

### Claim 2

An audio signal processor comprising:
a harmonic signal generator configured to generate a harmonic signal that includes a signal generated by frequency scaling components of a target audio signal by a factor of k (k is an integer equal to or more than 2), the target audio signal being an audio signal to be processed;
a left harmonic signal generator configured to generate a left harmonic signal by adjusting a gain of the harmonic signal in accordance with a direction of a target localization position of the target audio signal, such that the gain increases as the direction shifts leftward;
a right harmonic signal generator configured to generate a right harmonic signal by adjusting a gain of the harmonic signal in accordance with the direction of the target localization position of the target audio signal, such that the gain increases as the direction shifts rightward;
a left audio signal generator configured to generate a left audio signal by convolving a head-related transfer function from the target localization position to a left ear of a listener with the target audio signal;
a right audio signal generator configured to generate a right audio signal by convolving a head-related transfer function from the target localization position to a right ear of the listener with the target audio signal;
a left synthesizer configured to generate a left channel audio signal by synthesizing the left audio signal and the left harmonic signal; and
a right synthesizer configured to generate a right channel audio signal by synthesizing the right audio signal and the right harmonic signal.

### Claim 3

An audio signal processor comprising:
a harmonic signal generator configured to generate a harmonic signal that includes a signal generated by frequency scaling components of a target audio signal by a factor of k (k is an integer equal to or more than 2), the target audio signal being an audio signal to be processed;
a harmonic additional signal synthesizer configured to generate a harmonic additional signal by synthesizing the target audio signal and the harmonic signal;
a left channel audio signal generator configured to generate an audio signal of a left channel by convolving a head-related transfer function from a target localization position of the target audio signal to a left ear of a listener with the harmonic additional signal; and
a right channel audio signal generator configured to generate an audio signal of a right channel by convolving a head-related transfer function from the target localization position of the target audio signal to a right ear of the listener with the harmonic additional signal.

### Claim 4 (depends on 1)

The audio signal processor according to claim 1, wherein the harmonic signal generator is configured to generate signals, each generated by frequency scaling the components of the target audio signal by a factor of i, i taking integer values from 2 to n (n ≥ k and n > 2), and to generate the harmonic signal by synthesizing the generated signals.

### Claim 5

An audio signal processor comprising:
a left harmonic signal generator configured to generate a left harmonic signal generated by frequency scaling components of a target left channel signal by a factor of k (k is an integer equal to or more than 2), the target left channel signal being a left channel signal of a target audio signal including left and right channels to be processed;
a right harmonic signal generator configured to generate a right harmonic signal generated by frequency scaling components of a target right channel signal by a factor of L (L is an integer equal to or more than 2), the target right channel signal being the right signal of the target audio signal;
a left audio signal generator configured to generate a left audio signal by convolving a head-related transfer function from a target localization position of the target audio signal to a left ear of a listener with the target left channel signal;
a right audio signal generator configured to generate a right audio signal by convolving a head-related transfer function from the target localization position to a right ear of the listener with the target right channel signal;
a left synthesizer configured to generate a left channel audio signal by synthesizing the left audio signal and the left harmonic signal; and
a right synthesizer configured to generate a right channel audio signal by synthesizing the right audio signal and the right harmonic signal.

### Claim 6

An audio signal processor comprising:
a left harmonic signal generator configured to generate a left harmonic signal generated by frequency scaling components of a target left channel signal by a factor of k (k is an integer equal to or more than 2), the target left channel signal being a left channel signal of a target audio signal including left and right channels to be processed;
a right harmonic signal generator configured to generate a right harmonic signal generated by frequency scaling components of a target right channel signal by a factor of L (L is an integer equal to or more than 2), the target right channel signal being the right signal of the target audio signal;
a left harmonic additional signal synthesizer configured to generate a left harmonic additional signal by synthesizing the target left channel signal and the left harmonic signal;
a right harmonic additional signal synthesizer configured to generate a right harmonic additional signal by synthesizing the target right channel signal and the right harmonic signal;
a left channel audio signal generator configured to generate a left channel audio signal by convolving a head-related transfer function from a target localization position of the target audio signal to a left ear of a listener with the left harmonic additional signal; and
a right channel audio signal generator configured to generate a right channel audio signal by convolving a head-related transfer function from the target localization position to a right ear of the listener with the right harmonic additional signal.

### Claim 7 (depends on 5)

The audio signal processor according to claim 5, wherein:
the left harmonic signal generator is configured to generate signals, each generated by frequency scaling the components of the target left channel signal by a factor of i, i taking integer values from 2 to n (n ≥ k and n > 2), and to generate the left harmonic signal by synthesizing the generated signals; and
the right harmonic signal generator is configured to generate signals, each generated by frequency scaling the components of the target right channel signal by a factor of i, i taking integer values from 2 to m (m ≥ L and m > 2), and to generate the right harmonic signal by synthesizing the generated signals.