Daqarta
Data AcQuisition And Real-Time Analysis
Scope - Spectrum - Spectrogram - Signal Generator
Software for Windows
Science with your Sound Card!
The following is from the Daqarta Help system:

Features:

Oscilloscope

Spectrum Analyzer

8-Channel
Signal Generator

(Absolutely FREE!)

Spectrogram

Pitch Tracker

Pitch-to-MIDI

DaqMusiq Generator
(Free Music... Forever!)

Engine Simulator

LCR Meter

Remote Operation

DC Measurements

True RMS Voltmeter

Sound Level Meter

Frequency Counter
    Period
    Event
    Spectral Event

    Temperature
    Pressure
    MHz Frequencies

Data Logger

Waveform Averager

Histogram

Post-Stimulus Time
Histogram (PSTH)

THD Meter

IMD Meter

Precision Phase Meter

Pulse Meter

Macro System

Multi-Trace Arrays

Trigger Controls

Auto-Calibration

Spectral Peak Track

Spectrum Limit Testing

Direct-to-Disk Recording

Accessibility

Applications:

Frequency response

Distortion measurement

Speech and music

Microphone calibration

Loudspeaker test

Auditory phenomena

Musical instrument tuning

Animal sound

Evoked potentials

Rotating machinery

Automotive

Product test

Contact us about
your application!

Burst Rise


Macros: BurstRise, BurstRiseMod

This is the time or number of samples the burst waveform will take to rise from completely off to completely on. The shape of the rise is typically that of a cosine-power function, whose exponent is controlled by the Shape option. However, you may set the exponent to 0 to get a linear shape.

By making the rise longer, or the exponent smaller (not including 0 for linear), you reduce the amount of "spectral splatter" or audible click associated with the onset of the tone. In a detection experiment, the click might be audible where the tone itself is not, giving a misleading result.

But if you are determining the subject's detection threshold by recording neural responses, you must also take care not to make the rise too long, either, as explained in the Rise/Fall practical example for auditory evoked responses.


Burst Rise Modulation

Normally, you can ignore the small Rise pushbutton and just use the edit portion of the control. The button opens a Burst Time Modulator dialog that allows the Rise time to be modulated, either by a sine wave source with adjustable frequency and phase, or by some other stream source. You can also set the base Rise value from that dialog (it's just a duplicate of the main Rise control), as well as the modulation depth.

When modulation is applied, the effective Rise time is equal to the sum of the base Rise value plus the modulator scaled by the modulator depth. For example, if the depth is 10% then the effective Rise ranges from 90% to 110% of its base value. If the base Rise is 100 samples, the effective Rise will then range from 90 to 110 samples.


Macro Notes:

L.1.BurstRise=100 sets Left Stream 1 Burst Rise to 100 samples, assuming Smpl mode. It will set 100 seconds in sec mode. To be safe, use a SmplSec command to set the desired mode before using this command.

L.1.BurstRise=>1 increments and L.1.BurstRise=>-1 decrements by one sample, even in sec mode. Only +/-1 sample steps are allowed.

If the Burst Dialog is open, BurstRiseMod=1 opens the associated Burst Time Modulation dialog, BurstRiseMod=0 closes it, and BurstRiseMod=x toggles between open and closed. See further information under Burst Time Modulation.


See also Burst Rise/Fall vs. Spectral Width, Burst Overview, Burst Dialog Controls


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