| Author |
Message |
Jon Harris
Guest
|
 Posted:
Fri Apr 01, 2005 8:04 am Post subject:
Re: Is there an Open Source Echo Cancellation module availab |
|
|
"Robert Oschler" <no-mail-please@nospam.com> wrote in message
news:H7OdnQRFQPPpNtHfRVn-3A@adelphia.com...
| Quote: |
"Jon Harris" <goldentully@hotmail.com> wrote in message
news:3b35buF6dtkm0U1@individual.net...
"Jon Harris" <goldentully@hotmail.com> wrote in message
news:3b354nF6edbojU1@individual.net...
I should add, a better commercial example of what you want to do are the
echo
canceling systems used commonly in teleconferencing. They solve the
problem you
have, and do it in software (often with dedicated DSPs). However, even
with
these, usually at least the loudspeakers are fixed and often the
microphones are
fixed as well. But I would think a good fast-adapting echo canceller
might be
able to give you at least some attenuation of the robot's voice.
Jon,
Got any sources for any open source code I could try? I'm more than
willing to bang away at it. If not code, perhaps a really simplified
article with pseudo-code?
|
Sorry, I don't know of any source code. But there are many articles out there
on the subject that a Google search should turn up. Here's an introductory one:
http://www.spiritdsp.com/pdf/article_4.pdf
There are various algorithms for AEC, including time and frequency domain. Once
you get your brain around the different algorithms, maybe then you can try to
find some more specifics. |
|
| Back to top |
|
 |
Richard Owlett
Guest
|
| Posted:
Fri Apr 01, 2005 4:12 pm Post subject:
Coulld this be treated as a "speaker identification" problem |
|
|
Robert Oschler wrote:
| Quote: | [snip]
The Robosapien robot is a very loud robot which, using the average
speech detection/silence detection algorithms, will trigger a lot of
"false" recognition activity on the microphone; even on a decent
headset microphone. At about 3 feet away he still pumps out healthy
60+ decibels of sound which left unchecked, triggers the microphone
frequently and subsequently generating false recognition results.
I managed to do a very effective job at eliminating the problem using
some tricky volume thresholding, but in the future I'd like to go a
step further and use echo cancellation techniques to remove the
robot's "voice".
[snip]
|
Discussion indicates noise/echo cancellation is impractical in the
general case.
However the problem includes only two known "speakers".
On the surface it would appear that a speaker identification routine
gating the voice recognition function might work.
I'm guessing that the robot's voice is "very robotic". I found pictures
of the robot but no sound files.
I know little DSP and less speaker recognition. |
|
| Back to top |
|
|
Jitendra Rayala
Guest
|
|
| Back to top |
|
|
Robert Oschler
Guest
|
| Posted:
Sat Apr 02, 2005 1:31 am Post subject:
Re: Is there an Open Source Echo Cancellation module availab |
|
|
"Jitendra Rayala" <jrayala@hotmail.com> wrote in message
news:1112379164.057139.11400@f14g2000cwb.googlegroups.com...
Jitendra,
Thanks! I'll take a look.
Robert |
|
| Back to top |
|
|
Robert Oschler
Guest
|
| Posted:
Sat Apr 02, 2005 1:32 am Post subject:
Re: Coulld this be treated as a "speaker identification" pro |
|
|
"Richard Owlett" <rowlett@atlascomm.net> wrote in message
news:114qb4pk0hi8g6e@corp.supernews.com...
| Quote: |
Discussion indicates noise/echo cancellation is impractical in the
general case.
However the problem includes only two known "speakers".
On the surface it would appear that a speaker identification routine
gating the voice recognition function might work.
I'm guessing that the robot's voice is "very robotic". I found pictures
of the robot but no sound files.
I know little DSP and less speaker recognition.
Richard, |
Yes I considered that. It's one of the things I'm experimenting with now.
Thanks,
Robert |
|
| Back to top |
|
|
NS
Guest
|
| Posted:
Mon May 02, 2005 4:16 pm Post subject:
Re: Is there an Open Source Echo Cancellation module availab |
|
|
Your best bet for a great Acoustic Echo Canceler is probably at:
http://www.Compandent.com/products_echokiller.htm
http://www.Compandent.com/EchoKillerFactSheet.pdf
Robert Oschler wrote:
| Quote: | Hello,
I am the lead programmer for the SourceForge based Robosapien Dance Machine
project, released under the GPL license:
http://sourceforge.net/projects/robodance
I just added voice recognition capability to the program using another
SourceForge open source project, the Sphinx 3.5 speech recognition engine:
http://sourceforge.net/projects/cmusphinx
The Robosapien robot is a very loud robot which, using the average speech
detection/silence detection algorithms, will trigger a lot of "false"
recognition activity on the microphone; even on a decent headset microphone.
At about 3 feet away he still pumps out healthy 60+ decibels of sound which
left unchecked, triggers the microphone frequently and subsequently
generating false recognition results.
I managed to do a very effective job at eliminating the problem using some
tricky volume thresholding, but in the future I'd like to go a step further
and use echo cancellation techniques to remove the robot's "voice".
It would be very simple for me to record everything the robot says, each to
separate audio file. Since my program is controlling the robot, I always
know exactly what he is saying. Therefore, I should be able to take the
appropriate pre-recorded audio file of his voice and remove it from the
incoming microphone signal using spectral subtraction techniques.
But since I am not a DSP expert (that's an understatement), I'd be far
better off finding some open source code that I could include in the project
to perform the spectral subtraction.
I'd need the module to be able to take a pre-recorded file and create a
filter that would remove the audio in that file, from an audio signal in
real-time (live microphone input). I would need that filter to be able to
adapt to differences between the audio contained in the pre-recorded file,
and the way that audio will sound coming in on a different microphone than
the one the audio was originally recorded with, and at a different distance
from the microphone as the original (pre-recorded file versus actual audio
coming in from a new microphone).
Does anyone know of something I could use? I am a veteran, C/C++/Object
Pascal programmer and can even handle some assembler if needed.
Thank you if you have read this far, I know it's a long message. :)
Thanks,
|
|
|
| Back to top |
|
|
gal1264
Guest
|
| Posted:
Wed Dec 21, 2005 11:43 pm Post subject:
Re: Is there an Open Source Echo Cancellation module availab |
|
|
| Quote: | Andrew,
I thought about it but most of the ones I saw were in the $70+ range.
Since
my software is free, I'm trying to make entry into it as cheap a
possible.
I'm finding out that only a handful of my users are willing to spen
more
than around $15. If you know of anything, please let me know.
Thanks,
Robert
|
How much does the robot run? Might be worth the extra $$ to not have i
beat you up. On another note I did a similar project speech enabling som
segway soccer robots for the last robocup. We had great success by tunin
the key words/phrases based on testing in noisy environments, and m
experience in Speech Reco is that the quality of the prompts and grammar
is as valuable as ANY technology you can put in there.
-Tom |
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in