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