
Drone.vc – Request for Companies #1: Better Audio - dweekly
http://dronevc.tumblr.com/post/89525955649/drone-vc-rfc-1-better-audio
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dharma1
This isn't really a problem particular to drones. Most audio applications have
noise issues - room reverb, wind noise, background chatter, preamp noise etc.

A couple of options spring to mind:

1) Get a noise fingerprint from the rotors and clean the audio with DSP. Hard
because the noise of the rotors is constantly changing, but you could
potentially place several contact mics next to the rotors and then subtract
that from the main mic to get a cleaner signal

2) super directional audio with parabolic reflectors which reject audio
outside the narrow beam

3) Don't record audio from the drone! Use wireless mics on the ground instead

Disclaimer: Used to be an audio engineer in past life and have been running a
drone company for 3 years. We specialise in high end video (RED Epic), but are
also working on some non-cinematography applications at the moment. We have
both hardware and software teams. Any investors interested in hearing more,
you can get in touch at info@londonhelicam.co.uk

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dweekly
Dharma,

Great points!

#1 - my thought was someone very clever could use the ESC output to the motors
to estimate likely noise output from that rotor as well as measuring the
actual noise output.

#2 I'm genuinely curious about the pros and cons of flying with a parabolic vs
an array mic approach. It sounds like you could offer some insights here on a
tradeoff.

#3 Well, yes. [grin] But that doesn't exactly solve the problem asked for.

I'll drop you an email now - thanks for responding! ^_^

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kenrikm
Interesting David, myself and some of the guys at the office have been
experimenting with quads lately and discussing possible military/police or
media uses, after reading your initial proposal #1 struck me as a possible
solution. However I've since swapped to another much more "back to basic
principles" idea that while more difficult, would have a much wider impact.

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dshankar
Genuinely curious, let's assume this technology is created. What would audio
signals would you even record?

Most drones are far from any subject (sound-producing or not). What are use
cases where the drone is close to a sound source?

This got me thinking of a few examples:

    
    
      - drones could get closer to waterfalls or volcanoes than any sound engineer with a boom could
      - a drone could be used for video interviews, automatically panning between the interviewer & the interviewee, recording both video and pristine audio, streaming via a cellular data link back to the studio

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ninjay
Search and rescue missions? People could tell the drone operator how to help.

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jzwinck
Not to mention tell the operator if they are alive at all. It may not be
obvious if you see from a few meters away someone who is mostly immobilized by
a fallen whatever. For this sort of application, a microphone on a winched
cable might be useful (n.b.: make a feature to jettison the cable if it gets
stuck!).

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dweekly
Yes, strap a megaphone on here and now you've got a flying telephone for
search & rescue as well as a chance for an aerial director to talk with folks
in the ground without the need to set up a second comms channel (e.g. RF
radios).

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nl
Drone.vc, request for companies, and the first problem posted is "better
audio". Seriously? No one is working on it because there are approximately a
million and one drone related problems that _are actually worth solving_!

Solve the perching problem, or the loss of control channel problem, or better
image tracking or make them quieter or smaller or bigger or faster or can fly
higher or can carry heavier payload or...

But what do I know? Clearly it is the _sound_ that is holding back drone
companies from delivering VC level returns.

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dweekly
There are a _lot_ of interesting problems worth solving in the industry.
That's what makes it so exciting! What I'm going to do with this sequence is
try and point out a set of problems that are interesting that aren't being
solved. It could be that nobody is working on them because all of my ideas are
all really awful, but the hope is that some people may get inspired to tackle
some new problems in the space. I'm not going to claim that audio recording is
the singularly most important problem to solve (you seem to be implying that's
what I was getting at) but it is an interesting/common one and I hadn't seen
anyone working on it. There are another dozen of these tee'd up, some of which
address the other problems you've listed. It sounds like you have some good
opinions about what problems need to be solved! I'd love to see a response
with a little bit more meat than an ellipsis.

One of the _best_ responses to these will be to find companies already working
on these problems, just in secret. For instance, I had someone on Twitter let
me know that a company in Hilo, Hawai'i called DroneFlow is actually working
on some of these audio issues. I'll be reaching out. :)

BTW, researching perching led me to this beautiful thesis -
[http://groups.csail.mit.edu/locomotion/perching_media/CoryTh...](http://groups.csail.mit.edu/locomotion/perching_media/CoryThesis.pdf)
\- what's your take on this contribution to the space?

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twocommas
Forgive me if I'm missing something, it just looks like a single page Tumblr
account with a quick blurb about being a "Drone VC", with no details about the
people or firm behind it. Does anyone know who's behind "Drone VC" or have any
more information on it?

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shimms
Links to David E. Weekly's syndicate page on Angel List
([https://angel.co/dweekly/syndicate/](https://angel.co/dweekly/syndicate/))
who appears to be @dweekyl
([https://twitter.com/dweekly](https://twitter.com/dweekly)).

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dweekly
Yessir!

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Intermernet
Although this approach is technically awesome, can't someone just modify
existing noise cancellation technology with mics closer to the motors / props?
It's a horrible hack, and nowhere near as elegant, but it may work quite well
considering that no matter what signal is used for cancellation, it will be
difficult to discriminate wanted / unwanted sounds in the cancelled
frequencies.

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dweekly
It's quite possible that this "horrible hack" might be good enough! I'd love
to see people experimenting and coming up with answers about what works and
doesn't. :)

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dsl
[http://www.eeweb.com/blog/extreme_circuits/voice-
bandwidth-f...](http://www.eeweb.com/blog/extreme_circuits/voice-bandwidth-
filter)

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ddebernardy
It's surprising that intelligence agencies don't have a proper solution
already.

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cornellwright
Wouldn't the target notice if you flew a drone close enough to them to hear
them?

