Speech Enhancement Application. Which DSP?

Hello everybody

I hope I can get a little bit of help by posting this question.

I am new to DSPs, but I would like to learn and I plan to buy a DSP Starter 
Kit, but I do not know which one is suitable for the application I plan to 
implement on the DSP.....so I hope there are some experts out there who can 
recommend which DSPs I should look further into.

The application I am going to implement on the DSP is a real-time 
model-based speech enhancement application based on Hidden Markov Model. The 
observed speech is sampled at 8kHz and is assumed to be the sum of 2 
components: clean speech and stationary, pink noise and my job is to program 
an algorithm that can minimize noise with respect to the quality of the 
resulting speech.

This leads me to 2 questions:

[1] Based on the information I have given, which DSP Starter Kit should I 
choose?

[2] Which DSPs are typically used in speech enhancement applications?

I was told that using the Texas Instruments C671x DSP would be overkill for 
speech enhancement.

I hope I have provided enough info...

Thanks in advance...

 

Brother Numzi skrev:

> The application I am going to implement on the DSP is a real-time
> model-based speech enhancement application based on Hidden Markov Model. The
> observed speech is sampled at 8kHz and is assumed to be the sum of 2
> components: clean speech and stationary, pink noise and my job is to program
> an algorithm that can minimize noise with respect to the quality of the
> resulting speech.

Is the algorithm given, or is it your job to develop the algorithm?
The reason I am asking, is that it may be more efficient (what
development
time is concerned, not necessarily $$$) to get something like matlab
for
finding the algorithm. Matlab can read and play .wav files and have
everything you need for the maths. I doubt if you can get matlab
to work in real-time, though.

If, on the other hand, somebody else made the algorithm and you have
to implement it for real-time systems, then you need the DSP kit.

Rune

Hello Rune

I have 1 year to develop the algorithm and $$$ is not relevant in this 
project.

I plan to verify the functionality of the algorithm in matlab before I 
implement it on a DSP.

The degree of freedom in the algorithm design process is pretty high. 
However, there are certain demands... for example
the algorithm has to be based on theories such as Hidden Markov Modelling.

My main problem right now, however, is that I don't have the faintest idea 
about what kind of DSP I should choose
for such an application. As I stated earlier, I have been told that the TI 
C671x DSP is overkill. It can do what ever I need
it to do, but it is like choosing a castle for an ant to live in.......so I 
am wondering about what DSP starter kit I should buy
that can do the job without being too overdimensioned?

Thanks in advance - again :o)


---------------
> Is the algorithm given, or is it your job to develop the algorithm?
> The reason I am asking, is that it may be more efficient (what
> development
> time is concerned, not necessarily $$$) to get something like matlab
> for
> finding the algorithm. Matlab can read and play .wav files and have
> everything you need for the maths. I doubt if you can get matlab
> to work in real-time, though.
>
> If, on the other hand, somebody else made the algorithm and you have
> to implement it for real-time systems, then you need the DSP kit.
>
> Rune
> 

Brother Numzi wrote:
> Hello Rune
>
> I have 1 year to develop the algorithm and $$$ is not relevant in this
> project.
...
> so I am wondering about what DSP starter kit I should buy
> that can do the job without being too overdimensioned?

In order to specify a DSP, you need to know your requirements: memory,
mips, IO, etc. Once you have that, you can start to look at the DSPs
that cover your needs (including a comfortable margin).

Is this for educational purposes? Or do you, eventually, have to
deliver a piece of hardware where you can run the algorithm? If so, you
need to also consider chip cost vs. program development cost vs.
estimated number of hardware sales, and let that influence your choice.

Shooting from the hip, I would suggest a Blackfin EZ-Kit. If $$$ is not
relevant, it doesn't matter if you house the ant in the castle. Plus
there is a growing and active community for that chip where you should
be able to place your design sorrows.

Regards,
Andor

Brother Numzi skrev:
> Hello Rune
>
> I have 1 year to develop the algorithm and $$$ is not relevant in this
> project.
>
> I plan to verify the functionality of the algorithm in matlab before I
> implement it on a DSP.

Ah, good. That's all I wanted to know.

> The degree of freedom in the algorithm design process is pretty high.
> However, there are certain demands... for example
> the algorithm has to be based on theories such as Hidden Markov Modelling.
>
> My main problem right now, however, is that I don't have the faintest idea
> about what kind of DSP I should choose
> for such an application. As I stated earlier, I have been told that the TI
> C671x DSP is overkill. It can do what ever I need
> it to do, but it is like choosing a castle for an ant to live in.......so I
> am wondering about what DSP starter kit I should buy
> that can do the job without being too overdimensioned?

Sorry, can't help with that.

Rune

Brother Numzi wrote:

   ...

> My main problem right now, however, is that I don't have the faintest idea 
> about what kind of DSP I should choose
> for such an application. As I stated earlier, I have been told that the TI 
> C671x DSP is overkill. It can do what ever I need
> it to do, but it is like choosing a castle for an ant to live in.......so I 
> am wondering about what DSP starter kit I should buy
> that can do the job without being too overdimensioned?

Why don't you see what algorithm you need to implement, and account for 
any other tasks you'll need to accomplish, then decide on a processor 
when you have that information> Anyhow, there's nothing wrong with 
housing an ant in a castle if the castle is cheap enough.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

Rune Allnor skrev:
> Brother Numzi skrev:
> > it to do, but it is like choosing a castle for an ant to live in.......so I
> > am wondering about what DSP starter kit I should buy
> > that can do the job without being too overdimensioned?
>
> Sorry, can't help with that.
>
> Rune

...still can't but I do have some general remarks on what to consider
when considering. I write from the point of view that you are a student

starting on a final-year project (even though I have no reason to
believe you are) and need to prepare for a job after graduating.

Now, if $$$ is no concern of yours, and you can buy the latest, state-
of-the-art DSP numbercruncher, you could use this project as an
oportunity to get hands-on experience with the latest, hottest, meanest

monster of the business. Even if this means ant living in castles or
hunting rabbits with cruise missiles. The advantage is that you gain
experience with using the newest chips that will be around for some
time to come, and that might get you a job as a developer somewhere.

The other way of reasoning, is to buy a small DSP chip that is likely
not to be available for much longer, meaning that you will need to
learn how to program another DSP in a possible future job, putting
you at a slight disadvantage, compared to the "ant-in-the-castle"
approach, when applying for jobs. The gain in this situation, would
be that you get training in exploiting resource-limited systems.
The constraints on resources would probably be more similar to
whatever job you might get in the future, and thus the experience
of optimizing the use of scarce resources may be an advantage.

The scarce resources experience may be more generally useful,
in that you would understand the constraints of programming,
in a future manager job, even if you never program a single
line of code for the DSP after your current project.

So it may come down to a question of what is most useful to learn
first, exploiting scarce resources or learning how to program
the latest DSP architecture. 

FWIW, 

Rune

Excellent point, Rune. :o)

I am a student starting on my final-year project so I am very focused on
what I can do to better my chances of getting a job....

Which DSP should I choose then? (to improve my chances of getting a job)

Thanks in advance...

-------------------------
>
> Now, if $$$ is no concern of yours, and you can buy the latest, state-
> of-the-art DSP numbercruncher, you could use this project as an
> oportunity to get hands-on experience with the latest, hottest, meanest
>
> monster of the business. Even if this means ant living in castles or
> hunting rabbits with cruise missiles. The advantage is that you gain
> experience with using the newest chips that will be around for some
> time to come, and that might get you a job as a developer somewhere.
>

Brother Numzi wrote:
> Hello everybody
> 
> I hope I can get a little bit of help by posting this question.
> 
> I am new to DSPs, but I would like to learn and I plan to buy a DSP Starter 
> Kit, but I do not know which one is suitable for the application I plan to 
> implement on the DSP.....so I hope there are some experts out there who can 
> recommend which DSPs I should look further into.
> 
> The application I am going to implement on the DSP is a real-time 
> model-based speech enhancement application based on Hidden Markov Model. The 
> observed speech is sampled at 8kHz and is assumed to be the sum of 2 
> components: clean speech and stationary, pink noise and my job is to program 
> an algorithm that can minimize noise with respect to the quality of the 
> resulting speech.
> 
> This leads me to 2 questions:
> 
> [1] Based on the information I have given, which DSP Starter Kit should I 
> choose?

The ideal DSP starter kit for a project like this is a desktop PC. It is 
cheap, fast, readily available, has excellent development tools, is easy 
to program, and has exactly the audio and storage interfaces you need 
already in place.

> [2] Which DSPs are typically used in speech enhancement applications?

First my question: How long is this piece of string? There are many 
forms of speech enhancement. Some are single channel, and some 
multi-channel network applications. Most have to fit into the spare 
resources available on an existing DSP, such as in cellphone applications.

> I was told that using the Texas Instruments C671x DSP would be overkill for 
> speech enhancement.

For a multi-channel application is might be appropriate. For some really 
complex forms of enhancement, in multi-mic conference applications it 
might also be a sensible choice.

> I hope I have provided enough info...

Don't mess about with specialist DSP chips at this stage. Just get on 
with the real work in the PC environment you almost certainly possess 
right now.

Steve Underwood <steveu@dis.org> wrote in
news:dbsfv4$hrs$1@nnews.pacific.net.hk: 

> Brother Numzi wrote:
>> Hello everybody
>> 
>> I hope I can get a little bit of help by posting this question.
>> 
>> I am new to DSPs, but I would like to learn and I plan to buy a DSP
>> Starter Kit, but I do not know which one is suitable for the
>> application I plan to implement on the DSP.....so I hope there are
>> some experts out there who can recommend which DSPs I should look
>> further into. 
>> 
>> The application I am going to implement on the DSP is a real-time 
>> model-based speech enhancement application based on Hidden Markov
>> Model. The observed speech is sampled at 8kHz and is assumed to be
>> the sum of 2 components: clean speech and stationary, pink noise and
>> my job is to program an algorithm that can minimize noise with
>> respect to the quality of the resulting speech.
>> 
>> This leads me to 2 questions:
>> 
>> [1] Based on the information I have given, which DSP Starter Kit
>> should I choose?

You can probably use just about any of the dev kits for this application. 
You can also use one of our dspstak systems. We have boards that include 
a built in Analog Devices' EZ-Kit style debugger which is supported by 
the KIT (free) version of Visual DSP.

> 
> The ideal DSP starter kit for a project like this is a desktop PC. It
> is cheap, fast, readily available, has excellent development tools, is
> easy to program, and has exactly the audio and storage interfaces you
> need already in place.

I disagree with this statement. As I see this project, the main goal is 
learning. I think experience with a DSP platform is going to be more 
useful and important to a prospective employer. Most newly minted 
engineers could use more experience with hardware other than a desktop 
PC. In the general purpose DSP market, Analog Devices and TI have about 
equal market share. Experience with DSPs from either of these companies 
will be better than a PC. 

> 
>> [2] Which DSPs are typically used in speech enhancement applications?
> 
> First my question: How long is this piece of string? There are many 
> forms of speech enhancement. Some are single channel, and some 
> multi-channel network applications. Most have to fit into the spare 
> resources available on an existing DSP, such as in cellphone
> applications. 

I have done speech enhancement with DSPs that are far less powerful than 
a C67xx, Blackfin or SHARC. However, each of these DSPs are going to be 
better choices from a learning point of view.

We offer SHARC based products. I agree that with Andor that Blackfin 
would be a good choice as well. I am an ADI partisan, so I'll let someone 
else endorse the C671x.

> 
>> I was told that using the Texas Instruments C671x DSP would be
>> overkill for speech enhancement.

probably, so is the SHARC & Blackfin, so what?
> 
> For a multi-channel application is might be appropriate. For some
> really complex forms of enhancement, in multi-mic conference
> applications it might also be a sensible choice.
> 
>> I hope I have provided enough info...
> 
> Don't mess about with specialist DSP chips at this stage. Just get on 
> with the real work in the PC environment you almost certainly possess 
> right now.
> 

Sure, you can probably can use a PC, but a DSP will provide better 
experience.


-- 
Al Clark
Danville Signal Processing, Inc.
--------------------------------------------------------------------
Purveyors of Fine DSP Hardware and other Cool Stuff
Available at http://www.danvillesignal.com