densilcabrera / aarae Goto Github PK

Allow selection of both ASIO and non-ASIO output devices rather than forcing selection of ASIO drivers.
Noticed an issue on dell laptops with Realtek ASIO drivers.

Allow multi channel units for calibration and recording.
e.g. acceleration, pressure, intensity.

Hey, I am currently trying to use the function Fluctuation.m. After I calibrated the method to a fluctuation strength of 1 vacil for the 1 kHz sinusoid with a modulation frequency of 4 Hz and a sound pressure level of 60 dB (Cal = 0.0343, line 421) I tested this function with some signals.

When I use an ordinary sinusoid with a frequency of 1 kHz (60 dB SPL), a calibration value cal=94, a sampling rate of 44100, signaltype 0 (unmodulated) and soundfield 0 (free). The resulting fluctuation strength should really low (at about 0), but it is 0.4245.

The first thing I am curious is the calibration: I kept the value calconstant (line 32) on its value 0 and used a cal value of 94 as an input so the command window shows correctly:

rms level of the entire wave 60 dB

But when I observe now the variable audio which is multiplied with the factor 10.^(cal/20) it results in really high values for the time signal audio.

Then I looked through the code in debugging mode and saw the lines 333-338 which made me curious what is going to happen there:

333 dataIn = fft((N_b(:,currentFrame) .* window),N); % apply window to current frame
334 filteredOuter = filtfilt(b_outer,1,filtfilt(b_middle,1,dataIn)); % apply outer and middle ear filters
335 filteredOuterSpect = real(ifft(filteredOuter));
336 filteredOuterNyq = filteredOuterSpect(1:N/2+1);
337 filteredOuterNyq(2:end-1) = 2*filteredOuterNyq(2:end-1);
338 dataOut = filteredOuterNyq';

The input signal is fourier-transformed by an fft. Why is the filter applied to the resulting spectrum in line 334? In line 335 the resulting spectrum is transformed back into time-domain, but the operations in line 336 and 337 are obviously on a spectrum (take the single-sided spectrum). When I look now on the filtered output dataOut, the resulting spectrum doesnt look like a sinusoid anymore.

Is this an error in a code or am I maybe using the script in a wrong way? It would be greatful if you could provide me some help about this script.

Best regards

Florian Doleschal

Department of Experimental Audiology
Otto von Guericke University Magdeburg

chomalabel instead of chromalabel

use consistent 'audiodata' throughout aarae framework code, replacing all instances of 'signaldata'. Most importantly, we need to save structures with consistent field names to make post-processing code easier to write.