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85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04

0

10

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Adult

Children

Centers

Chronological changes of CI cases and CI Chronological changes of CI cases and CI centers in Japan centers in Japan (120 million population)(120 million population)

Bilateral Cochlear Implantation on the Bilateral Cochlear Implantation on the same daysame day

1) Sound direction 1) Sound direction identificationidentification

2) Speech perception in 2) Speech perception in quietquiet

3) Speech perception in 3) Speech perception in noise noise

a) Noise from fronta) Noise from front b) Noise from right and b) Noise from right and

leftleft

Binaural hearing with CI/HA or CI/CIBinaural hearing with CI/HA or CI/CI

Mechanism of sound source detection Mechanism of sound source detection Inter-aural time difference (IInter-aural time difference (I

TD)TD) Inter-aural level difference Inter-aural level difference

(ILD)(ILD)Normally hearing subjects Normally hearing subjects

ITD; 10 ITD; 10 μμsecsec ILD; 0.5 -1 dBILD; 0.5 -1 dB

can detect the difference in 2ºcan detect the difference in 2º

Sound direction identification with bilateral earsSound direction identification with bilateral ears

Bilateral cochlear implant subjectsBilateral cochlear implant subjects ITD; 400 ITD; 400 μμsec-1msecsec-1msec ILD; 1 dBILD; 1 dB

can detect the difference in 10-25º.can detect the difference in 10-25º.

Sound direction identification in Sound direction identification in bimodal (CI/HA) hearing modebimodal (CI/HA) hearing mode

③③

1.3m1.3m 1.3m1.3m①①

②② ④④

⑤⑤

　　　　　　　　

AudiometerAudiometer

SCB-40SCB-40

MethodsMethods

Stimulation:Stimulation:5 speakers at 45º 5 speakers at 45º

separationseparationwhite noise with white noise with

65dB SPL for 1 sec 65dB SPL for 1 sec 20 times from each 20 times from each

speakers at speakers at random sequencerandom sequence

Stimulation:Stimulation:5 speakers at 45º 5 speakers at 45º

separationseparationwhite noise with white noise with

65dB SPL for 1 sec 65dB SPL for 1 sec 20 times from each 20 times from each

speakers at speakers at random sequencerandom sequence

Judgment: Judgment: correct correct

22 near-missnear-miss

11 errorerror

00

Judgment: Judgment: correct correct

22 near-missnear-miss

11 errorerror

00

Subjects:Subjects: Two HA users Two HA users

whose hearing whose hearing levels were levels were symmetric.symmetric.

TT..SS.. MM..KK..

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××

××××××

××

××

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××

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0dB0dB

50dB50dB

100dB100dB

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Result of bilateral HA usersResult of bilateral HA users

Only 5 errors to the Only 5 errors to the adjacent speakers adjacent speakers out of 100 trialsout of 100 trials

Speakers: Speakers: 　　 trials trials (scores)(scores)L L （（ - 90°- 90° ））

F F （（ 0°0° ））

R R （（ 90°90° ））RA RA （（ 45°45° ））

LA LA （（ - 45°- 45° ））19/2019/20 （（ 39/4039/40 ））19/2019/20 （（ 39/4039/40 ））20/2020/20 （（ 40/4040/40 ））18/2018/20 （（ 38/4038/40 ））19/2019/20 （（ 39/4039/40 ））

95/10095/100 （（ 195/200195/200 ））

Threshold Time for useCase Age Gender

CauseDeafness

Durationdeafness CI HA C I H A

12

48 M Unknown 3 y 111.3 118.8 1y 4y

359 F Unknown １ ｙ１ ｙ S.O. 101.3 2y10m 20y

465 F Unknown ４ ｙ 106.3 92.5 1y6m 8y

571 M Unknown １ ｙ 101.3 96.3 3y 4y

680 F Unknown １ ｙ 108.8 107.5 1y10m 27 ｙ84 M Labyrinthitis １ ｙ 98.8 112.5 3y4m 8y

Threshold Time for useCase Age Gender

CauseDeafness

Durationdeafness Rt Lt Rt Lt

12

62 M Unknown 5 y 111.3 118.8 6 y 3 y32 F Unknown 17y S.O. 110.3 3 y 3 y

SubjectSubjectCI/HA

CI/CI

CI/HA: CI/HA: trials (scores)trials (scores)L L （（ - 90°- 90° ））

F F （（ 0°0° ））

R R （（ 90°90° ））RA RA （（ 45°45° ））

LA LA （（ - 45°- 45° ））11/2011/20 （（ 28/4028/40 ））

11/2011/20 （（ 30/430/400 ））10/2010/20 （（ 29/4029/40 ））

6/206/20 （（ 23/4023/40 ）） 9/209/20 （（ 26/4026/40 ））

46/10046/100 （（ 135/200135/200 ））

CI alone: CI alone: trials (scores)trials (scores)L L （（ - 90°- 90° ））

F F （（ 0°0° ））

R R （（ 90°90° ））RA RA （（ 45°45° ））

LA LA （（ - 45°- 45° ））7/207/20 （（ 19/4019/40 ））

9/209/20 （（ 29/4029/40 ）） 8/208/20 （（ 240/40240/40 ）） 7/207/20 （（ 24/4024/40 ）） 5/205/20 （（ 209/40209/40 ））

36/10036/100 （（ 115/200115/200 ））K.K.K.K.

L-CI/R-HAL-CI/R-HA

HAHA

CI/HACI/HA

CICI

Sound direction identification in Sound direction identification in binaural (CI/HA ) subjectsbinaural (CI/HA ) subjects

HA: trials (scores)HA: trials (scores)

L L （（ - 90°- 90° ））

F F （（ 0°0° ））

R R （（ 90°90° ））RA RA （（ 45°45° ））

LA LA （（ - 45°- 45° ）） 4/204/20 （（ 15/4015/40 ）） 4/204/20 （（ 16/4016/40 ）） 7/207/20 （（ 23/4023/40 ）） 5/205/20 （（ 19/4019/40 ）） 4/204/20 （（ 12/4012/40 ））

25/10025/100 （（ 85/20085/200 ））

Comparison of sound direction identification Comparison of sound direction identification scores in CI, CI-HA, HA conditionsscores in CI, CI-HA, HA conditions

100100

　　 00

5050

HAHACI+HACI+HACICI

P=0.001P=0.001

＊＊P=0.0197P=0.0197

＊＊＊＊＊＊

CI/HA groupCI/HA group

Binaural hearing with Binaural hearing with

CI and HA showed CI and HA showed

significantly better significantly better

score than monaural score than monaural

hearing (CI or HA hearing (CI or HA

alone) condition.alone) condition.

Binaural hearing with Binaural hearing with

CI and HA showed CI and HA showed

significantly better significantly better

score than monaural score than monaural

hearing (CI or HA hearing (CI or HA

alone) condition.alone) condition.

Comparison of sound direction identification Comparison of sound direction identification scores in CI alone and bilateral CI conditionsscores in CI alone and bilateral CI conditions

100100

　　 00

5050

Lt CILt CI Bil CIBil CI Rt CIRt CI

＊＊n.s.n.s.

CI/CI groupCI/CI group

Bilateral CI subjects Bilateral CI subjects

showed better score showed better score

than monaural listening than monaural listening

with poorer CI, but with poorer CI, but

showed similar showed similar

performance when performance when

listening with the better listening with the better

CI.CI.

Bilateral CI subjects Bilateral CI subjects

showed better score showed better score

than monaural listening than monaural listening

with poorer CI, but with poorer CI, but

showed similar showed similar

performance when performance when

listening with the better listening with the better

CI.CI.

Summary for sound direction Summary for sound direction identification studyidentification study

Binaural hearing with CI/HA had advantages Binaural hearing with CI/HA had advantages

for sound direction identification.for sound direction identification.

Benefits: Aware for the direction

of alarm sign. Can identify the speakerCan identify the speaker

while talking with many while talking with many

people.people.

1) Sound source detection 1) Sound source detection

2) Better speech perception 2) Better speech perception

especially in noisy especially in noisy

circumstancescircumstances

1) Sound source detection 1) Sound source detection

2) Better speech perception 2) Better speech perception

especially in noisy especially in noisy

circumstancescircumstances

Advantages of binaural hearingAdvantages of binaural hearing

Mechanisms of better hearing with two earsMechanisms of better hearing with two ears Summation effectSummation effect Binaural unmasking effect Binaural unmasking effect

(binaural squelch effect)(binaural squelch effect) Head shadow effect (advantage)Head shadow effect (advantage)

Mechanisms of better hearing with two earsMechanisms of better hearing with two ears Summation effectSummation effect Binaural unmasking effect Binaural unmasking effect

(binaural squelch effect)(binaural squelch effect) Head shadow effect (advantage)Head shadow effect (advantage)

CICI

NNSS

CICIHAHA

2) Speech perception in quiet2) Speech perception in quiet

　　 - summation effect – - summation effect – Speech perception score (%)Speech perception score (%) Speech reception threshold Speech reception threshold

(SRT in dB)(SRT in dB)

Binaural hearing with CI/HA or CI/CIBinaural hearing with CI/HA or CI/CI

Binmodal (CI/HA) hearing uBinmodal (CI/HA) hearing under quiet conditionnder quiet condition 　　

****

**

0

10

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30

40

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60

70

80

90

100 ****

***

**

*

40 50 60 70 80 85 9055 65 7535 45 (dB)

*

Comparison of speech perception sores Comparison of speech perception sores in three conditions (HA, CI, CI/HA)in three conditions (HA, CI, CI/HA)

***

0

10

20

30

40

50

60

70

80

90

100

**

*

40 50 60 70 80 85 9055 65 7535 45 (dB)

**

*

*

*HA

CI/HA

CI

Correct % for mono-syllabic words Correct % for mono-syllabic words in binaural and monaural conditionsin binaural and monaural conditions

CI+HA CI HA0

10

20

30

40

50

60

70

80

90

CI+HA CI HA0

10

20

30

40

50

60

70

80

90 (%)(%)

(CI/HA, CI-, HA-alone)(CI/HA, CI-, HA-alone)

(%)(%)

0

10

20

30

40

50

60

70

80

CI/CI Rt-CI Lt-CI

0

10

20

30

40

50

60

70

80

CI/CI Rt-CI Lt-CI

(CI/CI, CI alone)(CI/CI, CI alone)

Two parameters for speech perception testsTwo parameters for speech perception tests

Speech reception Speech reception threshold (dB)threshold (dB)

Speech reception Speech reception score (%)score (%)

Speech reception threshold (SRT) for HINT sentences under quiet condition

Six bimodal (CI/HA) subjects Six bimodal (CI/HA) subjects

CI+HA CI HA0

10

20

30

40

50

60

70

80

90dB(A)dB(A)

**

Two bilateral CI subjects Two bilateral CI subjects

0

10

20

30

40

50

60

Bil-CI Rt-CI Lt-CI

dB(A)dB(A)

Both speech perception score Both speech perception score

(%) and reception threshold (%) and reception threshold

(SRT) were better in listening (SRT) were better in listening

with two ears than listening with two ears than listening

with CI alone condition. with CI alone condition.

Both speech perception score Both speech perception score

(%) and reception threshold (%) and reception threshold

(SRT) were better in listening (SRT) were better in listening

with two ears than listening with two ears than listening

with CI alone condition. with CI alone condition.

Summary for speech perception in quietSummary for speech perception in quiet- Summation effect -- Summation effect -

SoundSoundfrom frontfrom front

CICIHAHA

SS

If SRT is better in 2dB, it If SRT is better in 2dB, it

corresponds to 10 15% better corresponds to 10 15% better

speech perception.speech perception.

If SRT is better in 2dB, it If SRT is better in 2dB, it

corresponds to 10 15% better corresponds to 10 15% better

speech perception.speech perception.

3) Speech perception 3) Speech perception in noisein noise

a) Noise from fronta) Noise from front- examination for - examination for bilateral unmasking bilateral unmasking (squelch) effect -(squelch) effect -

Binaural hearing with CI/HA or CI/CIBinaural hearing with CI/HA or CI/CI

Binaural hearing (CI/HA) Binaural hearing (CI/HA) under noisy circumstanceunder noisy circumstance

Sound and NoiseSound and Noisefrom frontfrom front

CICIHAHA

NNSS

Speech perception scores (%) under the noise Speech perception scores (%) under the noise from frontfrom front

100**

CI/HANoise

0

20

40

60

80

CIQuiet

CINoise

CI/HAQuiet

%

Binaural unmasking (squelch) effectBinaural unmasking (squelch) effect

Speech Sound: Speech Sound: 65dBSPL65dBSPL

Multi-talker noise:Multi-talker noise:60dBSPL60dBSPL

Hearing in noise test (HINT) in binaural Hearing in noise test (HINT) in binaural hearing subjectshearing subjects

Sound and NoiseSound and Noisefrom frontfrom front

CICIHAHA

NNSS

●

●

●

●

●

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●

○

●

●

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○ ○

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●

○

○ ○

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○

11

11

11

11 33

22 44 8866

55 77 99

1010

1111

1212

1313

1616 1818

17171515

1414 2020

191911

Intensity of Intensity of noisenoise (dB)(dB)

Speech Sound: Speech Sound: 65dB65dB

Multi-talker noise Multi-talker noise with variable with variable intensities at 2 dB intensities at 2 dB steps.steps.

Bil-CI Rt-CI Lt-CI0

2

4

6

8

10

12

14

16

18

HINT under the noise and speech from HINT under the noise and speech from the frontthe front

Binaural performance was better or as good as performance with the better ear alone under the condition with the speech and noise from front:

binaural unmasking (squelch) effect !!

S/N ratio (dB)S/N ratio (dB)

CI+HA CI0

5

10

15

20

25

P=0.04P=0.04

S/N ratio (dB)S/N ratio (dB)

**

3) Speech perception 3) Speech perception in noisein noise

b) Noise from b) Noise from different directionsdifferent directions

- examination for head - examination for head shadow effect -shadow effect -

Binaural hearing with CI/HA or CI/CIBinaural hearing with CI/HA or CI/CI

0

2

4

6

8

10

12

14

16

Rt-CI Lt-CI

S/N (dB)S/N (dB)

Noise from LtNoise from Lt

NN

CICI

CICI

SS

0

2

4

6

8

10

12

Rt-CI Lt-CI

S/N (dB)S/N (dB)

Noise from RtNoise from Rt

CICI

CICI

NNSS

“ “ Head shadow Head shadow advantage”advantage”

Monaural hearing under the noise Monaural hearing under the noise from right or leftfrom right or left

Front CI-side HA-side0

4

8

12

****

S/N (dB)S/N (dB)

Binaural hearing (CI/HA) under the noise Binaural hearing (CI/HA) under the noise from three directionsfrom three directions

For noise on the left or right side, binaural performance For noise on the left or right side, binaural performance can utilize can utilize “Head shadow advantage”.“Head shadow advantage”.

CICI

HAHA

SSNN

NN

NN

For noise on the left or right side, binaural performance For noise on the left or right side, binaural performance can utilize can utilize “Head shadow advantage”.“Head shadow advantage”.

NNSS

CICI

CICI

NN

NN

Binaural hearing (CI/CI) under the noise Binaural hearing (CI/CI) under the noise from three directionsfrom three directions

0

2

4

6

8

10

N-Front N-better N-poorer

S/N (dB)S/N (dB)

Conclusion -2-Conclusion -2-For the binaural hearing under the For the binaural hearing under the

noise condition “the head shadow noise condition “the head shadow

advantage” was large, while “binaural advantage” was large, while “binaural

unmasking effect” contributed little. unmasking effect” contributed little.

Karaoke bar in OsakaKaraoke bar in Osaka

END OF END OF

PRESENTATIONPRESENTATION END OF END OF

PRESENTATIONPRESENTATION

Auditory and visual information Auditory and visual information processing in auditory cortical processing in auditory cortical

areas of cochlear implant areas of cochlear implant usersusers ．．

- PET activation study -- PET activation study -