Resurrecting a mummys voice human vocal resilience

[Music]

i want to talk to you today

about how it is i talk to you

critical to human existence

is that our voices define who we are

my voice

is me your voice

is you

voice

is our main means of communication

evolved over millennia

and i want to argue today that there are

three

vocal resiliences for humans

we need our voices for all kinds of

things

we transmit verbal information ideas

feelings emotions

but more to the point

our identity

you answer the phone

and very often you recognize somebody

before they’ve even said what their name

is

it’s also the way we call for attention

if we’re in trouble

and of course

it also provides the lyrics

in singing

so

voice is fundamental to human living

in speech

in different acoustic situations in the

presence of competing sounds and in song

over

millennia

and part of what i want to say today

reflects on the millennial part of this

but first let’s look at the three

resiliencies

and before we do

i want just briefly to think about the

role of hearing

particularly the role of mankind’s

creation of devices that can play

very loud

sounds

sounds that are louder than any human

voice

can produce

through the application of electronics

so over roughly the last 130 years

we have the potential

to break the human communication voice

to ear train

because we are damaging

hearing

over just a century and a bit

having evolved over millennia our

communication system

so these are my three resiliencies the

first

is resilience to other sounds in the

environment

the second

is allowing us one

too many

communication

and the third

is to preserve the voice over millennia

but

i want us to remember there is little

resistance to loud

human-made

sounds

and that i would argue is an issue

that’s getting worse

we need to act to both understand the

problem and to protect

our hearing

many of us carry devices around

which can

cause hearing difficulty if you play

them too loud

and hearing issues of course

these are not on an

evolutionary time scale

these are on a very short time scale

so here’s the first one other sounds in

the environment

sounds of nature

we have evolved a redundancy in our

speech

specifically that allows us to hear

speech in the presence of natural sound

so if for example there’s a thunderstorm

or there’s heavy rain

then there is what we call masking in

the sound

and i’m going to do a little experiment

i want to demonstrate

that you can understand my voice

even if we cut the high end off or cut

the low end off

so the way we’re going to do this

is we’re going to listen to the low end

first

and i’m hoping that my microphone is

connected now to a filter as i

give you a demonstration of just the low

end and i hope you can still understand

me

and now would you switch it so we only

hear the high end a so-called high-pass

filter

i hope you all understood what i was

saying

now that means that if you’re only able

to hear the low end because of some high

frequency noise that’s in the

environment

we can still communicate as human beings

and vice versa if you can only hear the

high end because there’s rumbles of

thunder and other things going on

we can still communicate

it’s a wonder of vocal evolution

resilience two

now i have to admit i’m cheating

i am talking one to many

and i’m wearing this thing

and you can hear me because of the

loudspeakers

but if i was an opera singer on this

stage

i wouldn’t have a microphone i’d have an

orchestra between me and you and

loads of people in the auditorium

and yet you can hear the words of the

opera singer without a microphone

without loudspeakers

and the way they do it

is they engage

that aspect of the human voice which i

won’t use over a microphone

and the way that works is this

the voice box or the larynx the picture

in the middle

is here in the neck it’s where the

addams apple is

and of course we have two ears

when i do that kind of sound

i create a narrow tube as shown by the

light blue arrow in the larynx area

and that

tube

matches in

dimensions the tube here

and the tube here

so in engineering terms we set up

a transmitter and a receiver that are

tuned to work together

and again that is an even evolved way in

which the larynx has developed

to allow us to do it

and you don’t have to be a trained opera

singer

if you’re in danger

you know how to do this

because it’s a natural

something that’s stored in the brain

from evolution

which you can switch in

in time of real need

let me go to the third one now this is

the one that’s been alluded to

was the question that our group asked

can we recreate the sound of a three

thousand year old mummy

it’s an interesting question

and the answer is

that we can if we can recreate the tube

between the larynx and the lips because

that’s the tube the so-called vocal

tract the mouth and throat that i’m

using now as i speak to you

and if we take an mri image and there is

a photo of the mummy into going into the

mri machine

and we measure the airway in three

dimensions

and we then create

a 3d

image

and here is the very image

this is a 3d

plastic vocal tract and if i put it next

to mine you can see it’s about the right

shape

and we then put this on an artificial

larynx which is the loudspeaker in the

picture that’s two in from the top

we can then play a sound through the

loudspeaker

and we get the sound of this vowel

of course it’s not speech because to

speak i have to move my vocal tract i

have to move the articulators and this

of course is solid

but

in this particular case nezia moon the

hieroglyphics shown on the right there

in english

that hieroglyphic means true of voice

and nezumun wrote

that he expected his voice

to be heard in the afterlife

so this work was not just a technical

can we make the sound

it also had a message particularly to

egyptologists who study mummies

of something rather special

so we are hearing a voice

from three millennia ago

so

as i started my voice is me your voice

is you

our modern noisier world

is a challenge

and it’s a challenge from the last 100

to 150

years and it’s something that we need to

think about

we need to think about it in terms of

the numbers of humans who are getting

hearing problems

because of the noise around us

and if we’re going to thrive as humans

we need to communicate with each other

and we need our voices to do that

and i’ve suggested three areas of vocal

resist resilience

so please

look after yours thank you

oh hang on

hang on i’m sorry i just thought of

another one

just thought of another one

sound in space

drops by a factor of two over a certain

time

like many things

in life

but if you drop by a factor rather than

subtraction

technically

you never get to zero

i’ll leave you to think about that but

let’s just think of the implications

that means

that my talk today

and all the other talks

are still in this space

it also means that every single thing we

ever say inside

potentially

and that’s a big word potentially

might be recoverable one day

so be very careful what you say

thank you

you