Level Meter for visually disabled (blind) people

[Screaming_Rabbit]

Actually I'm thinking all my spare time about the MidiBox LC of my dreams I'd like to build for my personal studio.

Yesterday I had the first meeting for a project my employee threw me in.

I have to make a concept for a Digital Audio Workstation for a visually disabled woman who works at the same radio station I do, as a journalist for bachground storries and she has to cut her audio by herself.

I will take "Sequoia" www.samplitude.defor editing since it is possible to integrate it in DIGAS which is our Audio database manager software. Sequoia is supporting the Mackie protocol and all the editing is controllable by keyboard shortcuts which I will set on a programmable key matrix www.x-keys.com. The controllable keys are labled by braille letters (for touch reading with her fingers).

With the motorized faders of the MidiBox LC I'd like to build for her, she will be able to touch feel the current position of the level fader.

And now the big question:

I would apprechiate every idea about how I could make it possible, that the software  can tell her the current level metering position. It could be a average metering and also peaks / overloads should be displayed.

Greets and thanks for ideas and help

Roger

[Screaming_Rabbit]

Actually I'm thinking all my spare time about the MidiBox LC of my dreams I'd like to build for my personal studio.

Yesterday I had the first meeting for a project my employee threw me in.

I have to make a concept for a Digital Audio Workstation for a visually disabled woman who works at the same radio station I do, as a journalist for bachground storries and she has to cut her audio by herself.

I will take "Sequoia" www.samplitude.defor editing since it is possible to integrate it in DIGAS which is our Audio database manager software. Sequoia is supporting the Mackie protocol and all the editing is controllable by keyboard shortcuts which I will set on a programmable key matrix www.x-keys.com. The controllable keys are labled by braille letters (for touch reading with her fingers).

With the motorized faders of the MidiBox LC I'd like to build for her, she will be able to touch feel the current position of the level fader.

And now the big question:

I would apprechiate every idea about how I could make it possible, that the software  can tell her the current level metering position. It could be a average metering and also peaks / overloads should be displayed.

Greets and thanks for ideas and help

Roger

[moebius]

Well,

Not being rude:

She has more than "sensible enough" ears, I think?

"It could be a average metering and also peaks / overloads should be displayed."

 

Why?

Your radio stations "master limiter" will anyway fuck up any dynamics on the material, let it be 32bit or analogue tape, let it be -3dB peak or -30dB peak...

Just let her hear and feel..

Bye, Moebius

[moebius]

Well,

Not being rude:

She has more than "sensible enough" ears, I think?

"It could be a average metering and also peaks / overloads should be displayed."

 

Why?

Your radio stations "master limiter" will anyway fuck up any dynamics on the material, let it be 32bit or analogue tape, let it be -3dB peak or -30dB peak...

Just let her hear and feel..

Bye, Moebius

[Jack]

HI!

My Design Sugestion is build a mechanical replacement of level meter, something like this:

wfg

Jack

[Jack]

HI!

My Design Sugestion is build a mechanical replacement of level meter, something like this:

wfg

Jack

[Screaming_Rabbit]

She has more than "sensible enough" ears, I think?

... not sensible enough to tell absolute level, but shurely sensible to hear relative level (differences).

Your radio stations "master limiter" will anyway fuck up any dynamics on the material, let it be 32bit or analogue tape, let it be -3dB peak or -30dB peak...

... we're not an american style Hit-Radio station who's attitude is: "We have to be the loudest". We have 6 programs and only 2 of them are heavy compressed. On the other ones, we have from classical music to radio dramas with pretty much dynamics. And the master limiter processer has 150 bands and there for it is pretty important, that the audio material has the right level, otherwise it doesn't work the way we programmed it for.

About clipping: Even for a visual disabled person it's not possible to hear, when 10 samples are over 0dBFS. But she should be warned just as we audio engineers like to be warned, when we can't hear a clipping but the OL-LED shows us one.

... but thanks for your reply anyway!

Thanks Jack. I was thinking about something like that too. Almost like a braille module working with piezos. When I'd take the regular signal like for the LEDs, I think it would get pretty noisy. And how could I build that by myself? A spare braille module with 6 pins costs about $200  :-/

[Screaming_Rabbit]

She has more than "sensible enough" ears, I think?

... not sensible enough to tell absolute level, but shurely sensible to hear relative level (differences).

Your radio stations "master limiter" will anyway fuck up any dynamics on the material, let it be 32bit or analogue tape, let it be -3dB peak or -30dB peak...

... we're not an american style Hit-Radio station who's attitude is: "We have to be the loudest". We have 6 programs and only 2 of them are heavy compressed. On the other ones, we have from classical music to radio dramas with pretty much dynamics. And the master limiter processer has 150 bands and there for it is pretty important, that the audio material has the right level, otherwise it doesn't work the way we programmed it for.

About clipping: Even for a visual disabled person it's not possible to hear, when 10 samples are over 0dBFS. But she should be warned just as we audio engineers like to be warned, when we can't hear a clipping but the OL-LED shows us one.

... but thanks for your reply anyway!

Thanks Jack. I was thinking about something like that too. Almost like a braille module working with piezos. When I'd take the regular signal like for the LEDs, I think it would get pretty noisy. And how could I build that by myself? A spare braille module with 6 pins costs about $200  :-/

[smashtv]

Heya Roger!

Have you considered using a speakjet IC in standalone mode?  They can be programmed to trigger a spoken phrase or sound effect from one of it's 8 inputs, and it's capable of looping a chosen sound until another input happens (for tracking peaks that might happen when she is out of the room, etc.)

You could grab a signal from the peak overload led on the audio gear, buffer it, and use it to trigger the warning device.  

Or you could grab a signal from each of the last 8 LEDs and have the speakjet speak the status of the LEDs when a button is pressed.

Alternatively a MAX/MSP patch could be used to watch the level on a sound card's input, and speak the level on command, warn of overload, trigger external devices, etc.

Just launching some thoughts at ya.....  ;)

Very interested in the direction you take on this, please keep us informed!

Best!

Smash

[smashtv]

Heya Roger!

Have you considered using a speakjet IC in standalone mode?  They can be programmed to trigger a spoken phrase or sound effect from one of it's 8 inputs, and it's capable of looping a chosen sound until another input happens (for tracking peaks that might happen when she is out of the room, etc.)

You could grab a signal from the peak overload led on the audio gear, buffer it, and use it to trigger the warning device.  

Or you could grab a signal from each of the last 8 LEDs and have the speakjet speak the status of the LEDs when a button is pressed.

Alternatively a MAX/MSP patch could be used to watch the level on a sound card's input, and speak the level on command, warn of overload, trigger external devices, etc.

Just launching some thoughts at ya.....  ;)

Very interested in the direction you take on this, please keep us informed!

Best!

Smash

[moebius]

Ok,

When I'd take the regular signal like for the LEDs, I think it would get pretty noisy. And how could I build that by myself?

Why not using cheap servos or solenoids connected to buttons next to fader, that would be triggered by peaks indicating clipping?! So that when overload occurs, she would feel button rising?!

With servos, it could even be adapted, so that button would have few different positions relative to peak levels.

Bye, Moebius

[moebius]

Ok,

When I'd take the regular signal like for the LEDs, I think it would get pretty noisy. And how could I build that by myself?

Why not using cheap servos or solenoids connected to buttons next to fader, that would be triggered by peaks indicating clipping?! So that when overload occurs, she would feel button rising?!

With servos, it could even be adapted, so that button would have few different positions relative to peak levels.

Bye, Moebius

[Screaming_Rabbit]

Thanks Smash and Moebius

I didn't want to use "speak" since on the platform  a JAWS application is running which tells her the content of popups or windows status, so it could get pretty messy since she has to cut and mix audio as well.

Currently she uses one soundcard for all but I will change it, so the JAWS comments come from the internal soundcard with just one speaker in the middle and the produced audio comes from the Digigram VX card in Stereo LR. This way her mono parts come from LR which builds a phantom center position and the JAWS stuff really comes from the center. With that her brain will be able to better distinguisch the two different signals.

But I didn't think about a request button... good idea Smash!

I also like the servo thing... something like an index on a watch.

Would it be possible to smooth (kind like weight) the level signal in MIOS so the index wouldn't flutter that much?

For driving the servo I'd have to use an Analog Out, right? Is this possible on the same core with 8 MFs or would it need a additional core? (An additional core wouldn't be a financial problem since I have about $8000 budget for hardware)

Regards, Roger

[Screaming_Rabbit]

Thanks Smash and Moebius

I didn't want to use "speak" since on the platform  a JAWS application is running which tells her the content of popups or windows status, so it could get pretty messy since she has to cut and mix audio as well.

Currently she uses one soundcard for all but I will change it, so the JAWS comments come from the internal soundcard with just one speaker in the middle and the produced audio comes from the Digigram VX card in Stereo LR. This way her mono parts come from LR which builds a phantom center position and the JAWS stuff really comes from the center. With that her brain will be able to better distinguisch the two different signals.

But I didn't think about a request button... good idea Smash!

I also like the servo thing... something like an index on a watch.

Would it be possible to smooth (kind like weight) the level signal in MIOS so the index wouldn't flutter that much?

For driving the servo I'd have to use an Analog Out, right? Is this possible on the same core with 8 MFs or would it need a additional core? (An additional core wouldn't be a financial problem since I have about $8000 budget for hardware)

Regards, Roger

[smashtv]

But I didn't think about a request button... good idea Smash!

A request button is needed when using vocal/speech feedback in a control system, otherwise it will instantly annoy you with babbling in your ear :P

so it could get pretty messy since she has to cut and mix audio as well.

Sounds like she has enough to do ;)  

Have you thought about a pager-type device that vibrates with overload?

Seems like a non-touch sensitive motorfader with a custom cap and tactile mounting surface could be a way.  Should not be too hard to rig up a simple VU meter circuit that switches lines on a DIN module instead of driving LEDs, for eventual output via MIOS. This would probably need a "request" button also, otherwise I doubt the poor fader will last very long.   ;)

Just throwin' ideas...

Best!

Smash

[smashtv]

But I didn't think about a request button... good idea Smash!

A request button is needed when using vocal/speech feedback in a control system, otherwise it will instantly annoy you with babbling in your ear :P

so it could get pretty messy since she has to cut and mix audio as well.

Sounds like she has enough to do ;)  

Have you thought about a pager-type device that vibrates with overload?

Seems like a non-touch sensitive motorfader with a custom cap and tactile mounting surface could be a way.  Should not be too hard to rig up a simple VU meter circuit that switches lines on a DIN module instead of driving LEDs, for eventual output via MIOS. This would probably need a "request" button also, otherwise I doubt the poor fader will last very long.   ;)

Just throwin' ideas...

Best!

Smash

[Screaming_Rabbit]

Have you thought about a pager-type device that vibrates with overload?

Good Idea... I think for the overloads a piezo beeper would be o.k. too, since this shouldn't happen to many times. I have to ask her, about a "beep" is enough or about she should get information, on which track it happend. If she should get the track information, a speech processor or a Max/MSP patch would be a good idea again.

For the level information I think a resolution with a fader would be to precise.

Like Moebius wrote in his first post:

Your radio stations "master limiter" will anyway fuck up any dynamics on the material

... we have a processing unit on every program, thought we don't drive it as hard as he thought. I think something like 7 steps would be enough and solenoids (thx Moebius) would come in handy again:

- OL (for example: beeper)

- +9dB

- +6dB

- +3dB

-   0dB

-  -3dB

-  -6dB (and lower)

We use DIN metering which means: 0dB (+6dBU) eq. -9dBFS with 10dB/Sek. weighting on level deminishing (sorry... pretty hard for me to explain in english  :-[)

When the indicator shows her for example +6dB, this could be anything between -3 and -1dBFS. If the FS level goes down to between -4 and -6dBFS, the +3dB indicater would get active... and so on (her target level for the speech program she's producing is 0dB DIN). I think this would be precise enough and the mastering processor would do the rest. The steps even would come close to the weighting algorithm of the DIN scale. When I drive a spoken file at 0dB DIN it's fluttering at -7dB on the FS scale.

Thanks again for all this brain smoking  ;D

Greets, Roger

[Screaming_Rabbit]

Have you thought about a pager-type device that vibrates with overload?

Good Idea... I think for the overloads a piezo beeper would be o.k. too, since this shouldn't happen to many times. I have to ask her, about a "beep" is enough or about she should get information, on which track it happend. If she should get the track information, a speech processor or a Max/MSP patch would be a good idea again.

For the level information I think a resolution with a fader would be to precise.

Like Moebius wrote in his first post:

Your radio stations "master limiter" will anyway fuck up any dynamics on the material

... we have a processing unit on every program, thought we don't drive it as hard as he thought. I think something like 7 steps would be enough and solenoids (thx Moebius) would come in handy again:

- OL (for example: beeper)

- +9dB

- +6dB

- +3dB

-   0dB

-  -3dB

-  -6dB (and lower)

We use DIN metering which means: 0dB (+6dBU) eq. -9dBFS with 10dB/Sek. weighting on level deminishing (sorry... pretty hard for me to explain in english  :-[)

When the indicator shows her for example +6dB, this could be anything between -3 and -1dBFS. If the FS level goes down to between -4 and -6dBFS, the +3dB indicater would get active... and so on (her target level for the speech program she's producing is 0dB DIN). I think this would be precise enough and the mastering processor would do the rest. The steps even would come close to the weighting algorithm of the DIN scale. When I drive a spoken file at 0dB DIN it's fluttering at -7dB on the FS scale.

Thanks again for all this brain smoking  ;D

Greets, Roger

[smashtv]

I was looking for something else, and came across this Vibrating VU meter design from silicon chip magazine 3 years ago.

Best!

SmashTV

[smashtv]

I was looking for something else, and came across this Vibrating VU meter design from silicon chip magazine 3 years ago.

Best!

SmashTV

[Screaming_Rabbit]

THX Smash

... but I'd like to take the clipping info from the host software, since I want any clipping on any channel being sent to the vibrator, not only the analog master output of the soundcard.

Do you think it would be possible to drive the vibrating unit (propably taken from an old mobile telephone) directly with a digital out (right after the LED)?

I have to check on Sequoia, about when I select the peak hold function, there is also a peak hold in the Midi information.

Best regards

Roger

[Screaming_Rabbit]

THX Smash

... but I'd like to take the clipping info from the host software, since I want any clipping on any channel being sent to the vibrator, not only the analog master output of the soundcard.

Do you think it would be possible to drive the vibrating unit (propably taken from an old mobile telephone) directly with a digital out (right after the LED)?

I have to check on Sequoia, about when I select the peak hold function, there is also a peak hold in the Midi information.

Best regards

Roger

[moebius]

Hi,

Do you think it would be possible to drive the vibrating unit (propably taken from an old mobile telephone) directly with a digital out (right after the LED)?

Should be very easy. (LED output (hmm. even "matrix"ed?!) triggering transistor, switching motors power) And I have seen those "Vibrating motors" also sold as cheap Surplus.

Bye, Moebius

[moebius]

Hi,

Do you think it would be possible to drive the vibrating unit (propably taken from an old mobile telephone) directly with a digital out (right after the LED)?

Should be very easy. (LED output (hmm. even "matrix"ed?!) triggering transistor, switching motors power) And I have seen those "Vibrating motors" also sold as cheap Surplus.

Bye, Moebius

[uclaros]

Well, since both the ideas I had (solinoids and vibration) are allready proposed, there is only one left:

A mechanism that will generate some big voltage to a wire attached to the user's hand. The higher the level, the higher the voltage, just like the primitive video game on a James Bond movie (can't remember which!). Of course it may introduce humm in the console or even severe damage to the user if the level is accidently too high!

(kidding of course!)