envelope sine multiply

[TomTomTomTomTom]

Hello!

I´m working on my cochlear implant simulator and I have following problem. I want to multiply envelope signals with sine signal. I have tried few ways and checked help. It doesnt help me much. I need it because I want to reconstruct original speech signal. Do you have any clues? I have already spend half a day on this. I have LabVIEW 2013.

[TomTomTomTomTom]

Is my aproach correct? Other question, why I´m not able to play signal from OAT envelope detection.vi with play waveform.vi? 😞

[James_W]

1) Have you tried doing exactly what you just said in your first post - getting each waveform (Index the Data array)  and multiplying it by a generated perfect sine wave? - you are currently filtering the data, not multiplying with a sine wave

2) have you read the context help for playwaveform - have you selected the correct output device, is your sound output on in the OS etc.

James

[Henrik_Volkers]

Two things:

Try it with a DFT   and inverse DFT 🙂

and mix (add) all your signals first and then send one signal to the sound output.

[TomTomTomTomTom]

Hello!

I have made some progress.

I generate sine signal with sine wave.vi. I know that i need sine wave array with same length as input audio signal. I set sine wave array with constant samples. But how to correctly set frequency? I know that frequency settings  is the frequency of sine wave in normalized units of cycles/sample. But I dont understand how to correctly set this when I want for example sine wave with frequency 1000 Hz.

Than I need to multiply sine wave signal with envelope signal. Did I make it correctly? It doesnt work 😕

I tried to attach my VI file, but it says 'The contents of the attachment doesn't match its file type.'

[TomTomTomTomTom]

No one? 😕

[James_W]

Obvious answer:

Frequency = 1/Period

What you are currently doing is:

1) getting your data,

2) multiplying it by a sinewave - when multiplying arrays they should be the same size or you will be chopped to the shortest array.

3) Multiplying the resultant by 1000 - WHY? all this does is apply an arbirary gain to the waveform all the way along.

I believe you are using the wrong function:

look on the Signal Processing > Waveform Generation Palette for Sine Waveform.vi - this produces a sine wave of a frequency and amplitude (among other parameters)

See if this gets anywhere for you.

(As to why the slow replys, You last post was at 6pm UK time and the next one at 6:30am UK time. Most of us look at the forums in our breaks at work and so no-one in Europe was likely to reply, the US had a reasonable chance of getting you a reply everyone just tends to look at posts that interest them so if you were too far down the pages you wouldn't get a poke until anyone who had already posted bothered to look again.)

Good Luck

James

[Henrik_Volkers]

RTFM H(elpfiles)That really helps 😄

SO: first your output is decimated but you don't need the filter because this vi already do the filtering 🙂

SPAN defines half the filter bandwidth AND the output samplerate.

together with your original samplerate you can now do your sine amplitude scaling....

However my father has a cochlea implant and the way of exitation and how it affects the hearing nerves is different. But you can se it as a nice programming tutorial 😉

[TomTomTomTomTom]

Thank you guys, but this leads nowhere for me. I will have to try another aproach. Thank you for efforts!

Can I delete this?