# US 10,375,507 B2 · Measurement device and measurement method

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- Number: US 10,375,507 B2
- Document ID: US10375507B2
- Status: Granted
- Kind: B2
- Application number: 16/044,366
- Filed: 2018-07-24
- Published: 2018-11-15
- Granted: 2019-08-06
- Earliest claimed: 2016-01-26
- Assignees: JVC KENWOOD Corporation
- Applicants: JVC KENWOOD Corporation
- Inventors: Yumi Fujii; Hisako Murata; Masaya Konishi
- Web page: https://patentgrep.com/patent/US10375507B2

## CPC

- H04S 7/304: {For headphones}
- H04R 1/406: {microphones}
- H04R 3/005: {for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407)}
- H04R 5/033: Headphones for stereophonic communication {(details thereof, e.g. relating to batteries, cables or control elements H04R1/10)}
- 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)}
- 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)}
- H04S 7/302: {Electronic adaptation of stereophonic sound system to listener position or orientation (H04S7/301 takes precedence)}
- H04S 2400/01: Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved
- H04S 2400/15: Aspects of sound capture and related signal processing for recording or reproduction
- 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
- H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K)

## Abstract

A transfer characteristics measurement unit measures first transfer characteristics from left and right sound sources to left and right microphones, respectively. An environmental measurement unit picks up environmental measurement signals output from the left and right sound sources with use of the left and right microphones, sets an amplitude level of transfer characteristics measurement signals and a tap length of the transfer characteristics, picks up sounds with use of the left and right microphones in a state where no sound is output from the left and right sound sources, and measures second transfer characteristics. A correction unit corrects a low frequency range of the first transfer characteristics based on the second transfer characteristics.

## Claims

### Claim 1

A measurement device comprising:
a transfer characteristics measurement unit configured to measure first transfer characteristics from left and right sound sources to left and right microphones, respectively, by picking up transfer characteristics measurement signals output from the left and right sound sources by use of the left and right microphones;
an environmental measurement unit configured to perform first environmental measurement that picks up environmental measurement signals output from the left and right sound sources by use of the left and right microphones and second environmental measurement that picks up sounds by use of the left and right microphones in a state where no sound is output from the left and right sound sources, sets an amplitude level of the transfer characteristics measurement signals and a tap length of the first transfer characteristics based on results of the first environmental measurement, and measures second transfer characteristics based on results of the second environmental measurement; and
a correction unit configured to correct a low frequency range of the first transfer characteristics based on the second transfer characteristics.

### Claim 2 (depends on 1)

The measurement device according to claim 1, wherein
the environmental measurement unit sets a threshold for a frequency of the first transfer characteristics based on the second transfer characteristics, and
the correction unit corrects the first transfer characteristics in a frequency range lower than the threshold, and uses the first transfer characteristics in a frequency range higher than the threshold.

### Claim 3 (depends on 2)

The measurement device according to claim 2, wherein the correction unit replaces the first transfer characteristics with previously stored transfer characteristics in a frequency range lower than the threshold.

### Claim 4 (depends on 1)

The measurement device according to claim 1, wherein the correction unit corrects the first transfer characteristics by subtracting the second transfer characteristics from the first transfer characteristics.

### Claim 5 (depends on 1)

The measurement device according to claim 1, wherein the environmental measurement unit sets the tap length based on a sample position where the environmental measurement signals picked up by the left and right microphones converge.

### Claim 6

A measurement method for measuring first transfer characteristics between left and right sound sources and left and right microphones, the method comprising:
an environmental measurement step of performing first environmental measurement that picks up environmental measurement signals output from the left and right sound sources by use of the left and right microphones and second environmental measurement that picks up sounds by use of the left and right microphones in a state where no sound is output from the left and right sound sources, setting an amplitude level of transfer characteristics measurement signals and a tap length of the first transfer characteristics from the left and right sound sources to the left and right microphones based on results of the first environmental measurement, and measuring second transfer characteristics based on results of the second environmental measurement;
a transfer characteristics measurement step of measuring the first transfer characteristics by outputting, from the left and right sound sources, the transfer characteristics measurement signals set based on results of the first environmental measurement, and picking up the transfer characteristics measurement signals by use of the left and right microphones, respectively; and
a correction step of correcting a low frequency range of the first transfer characteristics based on the second transfer characteristics.

### Claim 7 (depends on 6)

The measurement method according to claim 6, wherein
the environmental measurement step sets a threshold for a frequency of the first transfer characteristics based on the second transfer characteristics, and
the correction step corrects the first transfer characteristics in a frequency range lower than the threshold, and uses the first transfer characteristics in a frequency range higher than the threshold.

### Claim 8 (depends on 7)

The measurement method according to claim 7, wherein the correction step replaces the first transfer characteristics with previously stored transfer characteristics in a frequency range lower than the threshold.

### Claim 9 (depends on 6)

The measurement method according to claim 6, wherein the correction step corrects the first transfer characteristics by subtracting the second transfer characteristics from the first transfer characteristics.

### Claim 10 (depends on 6)

The measurement method according to claim 6, wherein the environmental measurement step sets the tap length based on a sample position where the environmental measurement signals picked up by the left and right microphones converge.