/
More From Music More From Music

More From Music - PowerPoint Presentation

jane-oiler
jane-oiler . @jane-oiler
Follow
387 views
Uploaded On 2016-09-17

More From Music - PPT Presentation

m usic through a cochlear implant Dr Rachel van Besouw Hearing amp Balance Centre ISVR What a cochlear implant CI is and who can have one What a CI sound processor does How CI hearing compares to normal hearing ID: 467398

sound pitch hearing music pitch sound music hearing normal implant cochlea rainbow processor challenging cochlear amp music

Share:

Link:

Embed:

Download Presentation from below link

Download Presentation The PPT/PDF document "More From Music" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.


Presentation Transcript

Slide1

More From Music

m

usic through a cochlear implant

Dr Rachel van Besouw

Hearing & Balance Centre, ISVRSlide2

What a cochlear implant (CI) is and who can have one

What a CI sound processor doesHow CI hearing compares to normal hearing

Why music is particularly challenging for CI usersHow to get More From Music…

What will I learn in the next 25 minutes?Slide3

A CI is a surgically implanted device that electrically stimulates the auditory nerve fibres in the inner ear

Image courtesy of AB

What is a CI?Slide4

Ear canal

Pinna

Ear drum

Ossicles

(hammer, anvil & stirrup)

Image courtesy of AB

Cochlea

Auditory nerve

What is a CI?Slide5

Microphone(s)

Sound processor

Transmitter coil

Receiver coil & stimulator

Electrode array

Image courtesy of AB

What is a CI?Slide6

People with severe-to-profound

hearing loss in both ears

Due to abnormalities in the cochlea

Image courtesy of AB

Cochlea

Who is it for?Slide7

Aging

NoiseCertain medicines

Viral and bacterial infection (rubella, measles, meningitis) Ménière’s

diseaseGenetic origin

Premature birth

Head injury

Abnormal cochleae

Micrographs:

Keithley

, E.M. in: Ryan, A.F.

PNAS

2000;97:6939-6940

What causes this type of hearing loss?Slide8

What a cochlear implant (CI) is and who can have one

What a CI sound processor doesHow CI hearing compares to normal hearing

Why music is particularly challenging for CI usersHow to get More From Music…

What will I learn in the next 25 minutes?Slide9

What does a CI sound processor do?

microphone(s)

sound processor

transmitter coilSlide10

Sound processing stages

Pre-emphasis

(boosts frequencies important for speech

)

Automatic

gain control

(compresses the loudness range

)

Speech

enhancement

(reduces unwanted background noise)Slide11

Sound processing stages

Splits the sound signal into frequency bands

(the number of bands depends on the number of available electrodes)Slide12

Sound processing stages

Generates the pulse sequences for each electrodeSlide13

Sound processing stages

Sets the amplitude range for each electrode

(ensures that the amplitudes of the pulses are above threshold, but below the most comfortable loudness level)Slide14

Sound processing stages

Turns the data into a radio frequency (RF) signal for transmission to the implant Slide15

What a cochlear implant (CI) is and who can have oneWhat a CI sound processor

doesHow CI hearing compares to normal hearing

Why music is particularly challenging for CI usersHow to get More From Music…

What will I learn in the next 25 minutes?Slide16

decibels

120

110

100

90

80

70

60

50

40

30

20

10

0

-10

Loudness & Dynamic Range

loud

soft

How does a CI compare to normal hearing?Slide17

decibels

120

110

100

90

80

70

60

50

40

30

20

10

0

-10

Loudness & Dynamic Range

loud

soft

~20 dB range

How does a CI compare to normal hearing?Slide18

Pitch

How does a CI compare to normal hearing?Slide19

l

ow pitch region in cochlea

l

ow pitch info

high pitch info

high pitch region in cochlea

CI input

CI output

Pitch

How does a CI compare to normal hearing?Slide20

What a cochlear implant (CI) is and who can have one

What a CI sound processor doesHow CI hearing compares to normal hearing

Why music is particularly challenging for CI usersHow to get More From Music…

What will I learn in the next 25 minutes?Slide21

A visual analogy…

Why is music particularly challenging?

Image courtesy of Alan

OlleySlide22

Over the Rainbow

(Piano Only)

Some

where over the rainbow way up high

time

amplitude

Music…Slide23

Over the Rainbow

(Piano Only)

Some where over

the

rainbow way up high

frequency

(high

)

(low)

…is complexSlide24

Over the Rainbow

(Piano Only)

Over the Rainbow

(Piano Only)

Some where over

the

rainbow way up high

Filtered into >= 22 channels…

frequency

(high

)

(low)Slide25

… and turned into pulse sequences

Some where

ov

-

er

the rain-bow way up high…

Over the Rainbow

(Piano Only)Slide26

The normal cochlea has ~16,000 hair cells and many more nerve fibres, which provide fine pitch cues at different locations

Cochlear implants have between 12 and 22 electrodes and these can produce different pitches depending on their location

(the further into the cochlea, the lower the pitch)Some electrodes may sound the same, resulting in even fewer place pitch cues

Limited ‘place cues’ for pitchSlide27

The rate of the pulses delivered by the electrodes is

fixed and is usually too high to provide timing or ‘temporal’ cues about pitch

Temporal pitch cues from the envelope of the pulse sequences are there, but they are weak.Limited ‘temporal cues’ for pitchSlide28

More electrodes will not necessarily

result in better pitch perception due to:

current spread (each electrode affects a large area)the condition of the cochlea

(auditory nerve fibres may have degenerated)

What if we used more electrodes?Slide29

What a cochlear implant (CI) is and who can have one

What a CI sound processor doesHow CI hearing compares to normal hearing

Why music is particularly challenging for CI usersHow to get More From Music…

What will I learn in the next 25 minutes?Slide30

Whilst it is true that pitch is important for melody, melody is not essential

for musicRhythm is conveyed very well by the implant

Loudness cues (although compressed) can convey the dynamics of musicGross changes in the frequency spectrum are also conveyed by the implantMusic ≠ MelodySlide31

Music with clear changes in pitch

Music with a clear rhythm

Music will a simple arrangement

Appropriate volume

Quiet listening environment or direct input (TV/Hifi audio cable)

Clues for interpreting music (visual aids, lyrics

etc

)

Training & repetition…

?

What can help?Slide32

Interactive music awareness programme

24

x 30 min structured sessions Interactive software applications enabling users to manipulate music to suit their implant

Uses subtitled

video tutorials and written instructions

To be launched free online with a user forum ~Jan 2014 @

www.MoreFromMusic.orgSlide33

More From Music

Email us for further information…

Rachel:

rvb@isvr.soton.ac.uk

(project info, research collaboration)

Ben:

b.oliver@soton.ac.uk

(compositions, stems, software

)

Sarah:

s.m.hodkinson@soton.ac.uk

(professionals’ training)

Mary:

mlf@isvr.soton.ac.uk

(workshops for patients)o

r visit the music focus group websitewww.soton.ac.uk/mfg