SOUND PRESSURE ASSESSMENT SYSTEM, AND METHOD AND PROGRAM THEREOF

• US 20130070929A1
• Filed: 11/13/2012
• Published: 03/21/2013
• Est. Priority Date: 11/12/2010
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: ADACHI, Shinobu, KATO, Yumiko, MORIKAWA, Koji, OZAWA, Jun, NITTONO, Hiroshi
• Granted Patent: US 9,100,758 B2
• Time in Patent Office: Days
• US Class Current: 381/56
• CPC Class Codes: A61B 5/125 objective methods
• CPC Class Codes: A61B 5/38 Acoustic or auditory stimuli
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: H04R 29/001 for loudspeakers H04R29/007 takes precedence

Abstract

A sound pressure assessment system determines sounds to be presented by referring to a database retaining data of sounds, each of which is a pure tone. The system presents the determined sound as a first sound, and in a predetermined time after presenting the first sound, presents as a second sound a sound at least having the same frequency and the same sound pressure level as those of the'"'"'first sound to the user. The system extracts an amount of change from an N1 component in response to the first sound to that in response to the second sound. The N1 components are negative components of an user'"'"'s event-related potential based on points of presenting the first and second sounds as respective starting points. The system determines whether the sound pressure level of the presented sound is excessive to the user, based on the amount of change.

Claims

1. A sound pressure assessment system comprising:

a biological signal measurement section configured to measure an electroencephalogram signal of a user;

a sound database retaining data of a plurality of sounds, each sound being a pure tone;

a presentation sound determination section configured to determine a sound to be presented by referring to the sound database;

an output section configured to present the sound determined by the presentation sound determination section as a first sound to the user, and in a predetermined time after presenting the first sound, configured to present as a second sound a sound at least having a same frequency and a same sound pressure level as those of the first sound to the user;

an amount-of-change extraction section configured to extract an amount of change from an N1 component in response to the first sound to an N1 component in response to the second sound, the N1 component in response to the first sound being a negative component of an event-related potential of the electroencephalogram signal based on a point of presenting the first sound as a starting point, the N1 component in response to the second sound being a negative component of an event-related potential of the electroencephalogram signal based on a point of presenting the second sound as a starting point; and

an annoyance determination section configured to determine whether the sound pressure level of the presented sound is excessive to the user, based on the amount of change extracted by the amount-of-change extraction section.

2. The sound pressure assessment system of claim 1, wherein,

as the amount of change, the amount-of-change extraction section determines an amplitude ratio obtained by dividing an amplitude derived from the N1 component in response to the second sound by an amplitude derived from the N1 component in response to the first sound;

and

the annoyance determination section compares the amount of change against a predetermined threshold value, and if the amount of change is smaller than the predetermined threshold value, determines that the sound pressure level of the presented sound is annoying to the user, and if the amount of change is equal to or greater than the predetermined threshold value, determines that the sound pressure level of the presented sound is an appropriate sound pressure level for the user.

3. The sound pressure assessment system of claim 1, wherein,

the output section presents a plurality of pairs of stimulations, each pair including a said first sound and a said second sound;

and

for each pair of stimulations, the amount-of-change extraction section extracts an amount of change from an amplitude of a P1 component in response to the first sound, the P1 component being a positive component of an event-related potential of the electroencephalogram signal based on the point of presenting the first sound as a starting point, to an amplitude of a P1 component in response to the second sound, the P1 component being a positive component of an event-related potential of the electroencephalogram signal based on the point of presenting the second sound as a starting point, takes an arithmetic mean of event-related potentials of the extracted electroencephalogram signal for each of the first sounds and the second sounds of the plurality of pairs, and extracts as the amount of change a ratio of;

a difference between an arithmetic-meaned amplitude value of the P1 component in response to the first sound and an arithmetic-meaned amplitude value of the N1 component in response to the first sound; and

a difference between an arithmetic-meaned amplitude value of the P1 component in response to the second sound and an arithmetic-meaned amplitude value of the N1 component in response to the second sound.

4. The sound pressure assessment system of claim 1, wherein,

as the amount of change, the amount-of-change extraction section determines an absolute value of the difference between an amplitude derived from the N1 component in response to the second sound and an amplitude derived from the N1 component in response to the first sound;

and

the annoyance determination section compares the amount of change against a predetermined threshold value, and if the amount of change is equal to or greater than the predetermined threshold value, determines that the sound pressure level of the presented sound is annoying to the user, and if the amount of change is smaller than the predetermined threshold value, determines that the sound pressure level of the presented sound is an appropriate sound pressure level for the user.

5. The sound pressure assessment system of claim 1, wherein the N1 component is a negative component of an event-related potential in a range from 80 ms to 130 ms after a point of presenting the first sound or the second sound from the output section.

6. The sound pressure assessment system of claim 3, wherein the P1 component is a positive component of an event-related potential in a range from 30 ms to 70 ms after a point of presenting the first sound or the second sound from the output section.

7. The sound pressure assessment system of claim 5, wherein,

the sound database retains each sound in association with at least one sound characteristic feature, the at least one sound characteristic feature including a right or left ear of the user to which the sound is presented, a frequency of the sound, and/or a sound pressure level of the sound;

and

the amount-of-change extraction section takes an arithmetic mean of event-related potentials of the electroencephalogram signal for each of the first sound and the second sound and each sound characteristic feature.

8. The sound pressure assessment system of claim 3, wherein,

the amount-of-change extraction section calculates a P1-N1 amplitude concerning an event-related potential in response to the first sound or the second sound, the P1-N1 amplitude being a difference between a positive peak value of an event-related potential from 30 ms to 70 ms after the point of presenting the first sound or the second sound as a starting point and a negative peak value from 80 ms to 150 ms after the point of presenting the first sound or the second sound as a starting point, and extracts as the amount of change an amplitude ratio between the P1-N1 amplitude in response to the second sound and the P1-N1 amplitude in response to the first sound;

and

if the amplitude ratio is smaller than a first threshold value, the annoyance determination section determines that the sound pressure level of the presented sound is annoying to the user, and if the amplitude ratio is equal to or greater than the first threshold value, the annoyance determination section determines that the sound pressure level of the presented sound is an appropriate sound pressure level for the user.

9. The sound pressure assessment system of claim 8, wherein the first threshold value is 0.5.

10. The sound pressure assessment system of claim 1, wherein,

the output section presents a plurality of pairs of stimulations, each pair including a said first sound and a said second sound;

and

for each pair of stimulations, the amount-of-change extraction section extracts a P2 component in response to the first sound, the P2 component being a positive component of the electroencephalogram signal from 160 ms to 250 ms after the point of presenting the first sound as a starting point, and a P2 component in response to the second sound, the P2 component being a positive component of the electroencephalogram signal from 160 ms to 250 ms after the point of presenting the second sound as a starting point, takes an arithmetic mean of event-related potentials of the extracted electroencephalogram signal for each of the first sounds and the second sounds of the plurality of pairs, and extracts as the amount of change a ratio of;

a difference between an arithmetic-meaned amplitude value of the P2 component in response to the first sound and an arithmetic-meaned amplitude value of the N1 component in response to the first sound;

to a difference between an arithmetic-meaned amplitude value of the P2 component in response to the second sound and an arithmetic-meaned amplitude value of the N1 component in response to the second sound.

11. The sound pressure assessment system of claim 10, wherein,

the amount-of-change extraction section calculates an N1-P2 amplitude concerning an event-related potential in response to the first sound or the second sound, the N1-P2 amplitude being a difference between a negative peak value from 80 ms to 150 ms after the point of presenting the first sound or the second sound as a starting point and a positive peak value of an event-related potential from 160 ms to 250 ms after the point of presenting the first sound or the second sound as a starting point, and extracts as the amount of change an amplitude ratio between the N1-P2 amplitude in response to the second sound and the N1-P2 amplitude in response to the first sound;

and

if the amplitude ratio is smaller than a second threshold value, the annoyance determination section determines that the sound pressure level of the presented sound is annoying to the user, and if the amplitude ratio is equal to or greater than the second threshold value, the annoyance determination section determines that the sound pressure level of the presented sound is an appropriate sound pressure level for the user.

12. The sound pressure assessment system of claim 11, wherein the second threshold value is 0.55.

13. The sound pressure assessment system of claim 1, wherein the output section presents a plurality of pairs of stimulations, each pair including a said first sound and a said second sound, and presents a pair of stimulations of a different frequency from that of any immediately previously-presented pair of stimulations.

14. The sound pressure assessment system of claim 1, further comprising:

a hearing threshold level input section configured to receive a hearing threshold value of the user; and

an uncomfortable level prediction section configured to predict an uncomfortable level of the user based on the hearing threshold value having been input to the hearing threshold level input section, wherein

the presentation sound determination section determines the first sound and second sound from within a predetermined range around the uncomfortable level predicted by the uncomfortable level prediction section.

15. A sound pressure assessment apparatus comprising:

a presentation sound determination section configured to determine a sound to be presented by referring to a sound database retaining data of a plurality of sounds, each sound being a pure tone;

an output section configured to present the sound determined by the presentation sound determination section as a first sound to the user, and in a predetermined time after presenting the first sound, configured to present as a second sound a sound at least having a same frequency and a same sound pressure level as those of the first sound to the user;

an amount-of-change extraction section configured to extract an amount of change from an N1 component in response to the first sound to an N1 component in response to the second sound, the N1 component in response to the first sound being a negative component of an event-related potential of the electroencephalogram signal based on a point of presenting the first sound as a starting point, the N1 component in response to the second sound being a negative component of an event-related potential of the electroencephalogram signal based on a point of presenting the second sound as a starting point; and

an annoyance determination section configured to determine annoyance with respect to the sound pressure level of the presented sound, based on the amount of change extracted by the amount-of-change extraction section.

16. A sound pressure assessment system comprising:

a biological signal measurement section configured to measure an electroencephalogram signal of a user;

a sound database retaining data of a plurality of sounds, each sound being a pure tone;

a presentation sound determination section configured to determine a sound to be presented by referring to the sound database;

an output section configured to present the sound determined by the presentation sound determination section as a first sound to the user, and in a predetermined time after presenting the first sound, configured to present as a second sound a sound at least having a same frequency and a same sound pressure level as those of the first sound to the user;

an amount-of-change extraction section configured to extract an amount of change from an event-related potential in a zone from −

100 milliseconds to 400 milliseconds based on a point of presenting the first sound as a starting point, to an event-related potential in a zone from −

100 milliseconds to 400 milliseconds based on a point of presenting the second sound as a starting point; and

an annoyance determination section configured to determine whether the sound pressure level of the presented sound is excessive to the user, based on the amount of change extracted by the amount-of-change extraction section.

17. A sound pressure assessment method comprising the steps of:

measuring an electroencephalogram signal of a user;

determining a sound to be presented to the user;

presenting the determined sound to as a first sound to the user, and in a predetermined time after presenting the first sound, presenting as a second sound the same sound as the first sound to the user;

extracting an amount of change from an N1 component in response to the first sound to an N1 component in response to the second sound, the N1 component in response to the first sound being a negative component of an event-related potential of the electroencephalogram signal based on a point of presenting the first sound as a starting point, the N1 component in response to the second sound being a negative component of an event-related potential of the electroencephalogram signal based on a point of presenting the second sound as a starting point; and

determining annoyance with respect to the sound pressure level of the presented sound, based on the extracted amount of change.

18. The sound pressure assessment method of claim 17, wherein the step of determining annoyance compares the amount of change against a predetermined threshold value, and if the amount of change is smaller than the predetermined threshold value, determines that the sound pressure level of the presented sound is annoying to the user, and if the amount of change is equal to or greater than the predetermined threshold value, determines that the sound pressure level of the presented sound is an appropriate sound pressure level for the user.

19. A computer program stored on a non-transitory computer-readable medium, to be executed by a computer,

wherein the computer program causes the computer to execute the steps of:

receiving an electroencephalogram signal of a user;

determining a sound to be presented to the user;

presenting the determined sound to as a first sound to the user, and in a predetermined time after presenting the first sound, presenting as a second sound the same sound as the first sound to the user;

extracting an amount of change from an N1 component in response to the first sound to an N1 component in response to the second sound, the N1 component in response to the first sound being a negative component of an event-related potential of the electroencephalogram signal based on a point of presenting the first sound as a starting point, the N1 component in response to the second sound being a negative component of an event-related potential of the electroencephalogram signal based on a point of presenting the second sound as a starting point; and

determining annoyance with respect to the sound pressure level of the presented sound, based on the extracted amount of change.

20. The computer program of claim 19, wherein the step of determining annoyance compares the amount of change against a predetermined threshold value, and if the amount of change is smaller than the predetermined threshold value, determines that the sound pressure level of the presented sound is annoying to the user, and if the amount of change is equal to or greater than the predetermined threshold value, determines that the sound pressure level of the presented sound is an appropriate sound pressure level for the user.