acousticLoudness() function incorrect?
I decided to verify acousticLoudness function using ISO532-1 test method using ISO provided test signals and compare to stated sone levels.
According to ISO532-1 test signal wav data should be calibrated: " For the calibration of the WAVE files, 0 dB (relative to full scale) shall correspond to a sound pressure level of 100 dB." The calibration factor works out to be =2. This could be immediately verified by comparing test frequency amplitude after calibration with file name e.g. "Test signal 6 (tone 250 Hz 30 dB – 80 dB).wav". The max amplitude is 0.2 Pa (80dB).
I used these function parameters to calculate loudness of time varying noise signals:
LoudnessISO532=acousticLoudness(signal,48000,’SoundField’,’free’,’TimeVarying’,true);
acousticLoudness() produces loudness nearly twice the value of the ISO calculation. I discovered, however, that if I do not calibrate the wav file, function produces correct results.
Thus, it seems to me, to obtain correct results, calibrated SPL (Pa) signal should be reduced by half.
Did anybody try to verify the function using ISO532-1 test wav files? Did you calibrate them?
Thanks!I decided to verify acousticLoudness function using ISO532-1 test method using ISO provided test signals and compare to stated sone levels.
According to ISO532-1 test signal wav data should be calibrated: " For the calibration of the WAVE files, 0 dB (relative to full scale) shall correspond to a sound pressure level of 100 dB." The calibration factor works out to be =2. This could be immediately verified by comparing test frequency amplitude after calibration with file name e.g. "Test signal 6 (tone 250 Hz 30 dB – 80 dB).wav". The max amplitude is 0.2 Pa (80dB).
I used these function parameters to calculate loudness of time varying noise signals:
LoudnessISO532=acousticLoudness(signal,48000,’SoundField’,’free’,’TimeVarying’,true);
acousticLoudness() produces loudness nearly twice the value of the ISO calculation. I discovered, however, that if I do not calibrate the wav file, function produces correct results.
Thus, it seems to me, to obtain correct results, calibrated SPL (Pa) signal should be reduced by half.
Did anybody try to verify the function using ISO532-1 test wav files? Did you calibrate them?
Thanks! I decided to verify acousticLoudness function using ISO532-1 test method using ISO provided test signals and compare to stated sone levels.
According to ISO532-1 test signal wav data should be calibrated: " For the calibration of the WAVE files, 0 dB (relative to full scale) shall correspond to a sound pressure level of 100 dB." The calibration factor works out to be =2. This could be immediately verified by comparing test frequency amplitude after calibration with file name e.g. "Test signal 6 (tone 250 Hz 30 dB – 80 dB).wav". The max amplitude is 0.2 Pa (80dB).
I used these function parameters to calculate loudness of time varying noise signals:
LoudnessISO532=acousticLoudness(signal,48000,’SoundField’,’free’,’TimeVarying’,true);
acousticLoudness() produces loudness nearly twice the value of the ISO calculation. I discovered, however, that if I do not calibrate the wav file, function produces correct results.
Thus, it seems to me, to obtain correct results, calibrated SPL (Pa) signal should be reduced by half.
Did anybody try to verify the function using ISO532-1 test wav files? Did you calibrate them?
Thanks! acousticloudness MATLAB Answers — New Questions
