function?analyzeSignal（xFs）

%?ANALYZESIGNAL?Evaluates?dBA?level?of?input?signal.
%????ANALYZESIGNAL?Uses?a?sliding?window?to?evaluate?the
%????signal?level?（in?dBA）.?Results?are?graphed?for?
%????comparison?to?known?dBA?level?values.
%
%?Author:?Douglas?R.?Lanman?11/22/05

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%?Set?analysis?options.

%?Choose?response?type.
%?Note:?{‘fast‘?=?~125?ms?‘slow‘?=?~1.0?s}
responseType?=?‘slow‘;

%?Set?calibration?constant.
%?Note:?A?quite?location?will?be?~55?dBA.
C?=?72;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%?Part?I:?Analyze?input?signal.

%?Load?default?wave?sound?file?（if?none?provided）.
%?See:?http://www.swarthmore.edu/NatSci/sciproject/noise/noisequant.html
if?~exist（‘x‘）
???[xFsnBits]?=?wavread（‘./examples/trashtruck.wav‘）;
???t?=?（1/Fs）*[0:（length（x）-1）];?t?=?t+81;
else
???%?Determine?sample?times.
???t?=?（1/Fs）*[0:（length（x）-1）];
end

%?Determine?FFT?window?size.
%?Note:?Use?nearest?power?of?two?for?response?type.
if?strcmp（responseType‘slow‘）
???duration?=?1.0;
else
???duration?=?0.125;
end
N?=?ceil（duration*Fs）;
N?=?2^nextpow2（N）;

%?Estimate?signal?level?（within?each?windowed?segment）.
windowStart?=?[1:N:（length（x）-N）];
dBA?=?zeros（length（windowStart）1）;
windowTime?=?t（windowStart+round（（N-1）/2））;
for?i?=?[1:length（windowStart）]
???[XdBA（i）]?=?estimateLevel（x（windowStart（i）-1+[1:N]）FsC）;
end


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%?Part?II:?Plot?results.

%?Plot?input?signal.
figure（2）;?clf;
plot（tx）;
title（‘Input?Signal‘）;
xlabel（‘Elapsed?Time?（sec.）‘）;
ylabel（‘Normalized?Voltage‘）;
xlim（[t（1）?t（end）]）;
grid?on;

%?Plot?estimated?signal?level.
figure（3）;?clf;
plot（windowTimedBA‘LineWidth‘2）;
title（‘A-weighted?Signal?Level‘）;
xlabel（‘Elapsed?Time?（sec.）‘）;
ylabel（‘Signal?Level?（dBA）‘）;
xlim（[t（1）?t（end）]）;
grid?on;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????2070??2005-11-29?12:54??analyzeSignal.m
?????文件?????????808??2005-11-29?12:37??estimateLevel.m
?????文件????????1114??2005-11-29?12:40??filterA.m
?????文件????????1673??2005-11-30?00:31??initDisplay.m
?????文件????????1064??2005-11-29?19:12??initSoundCard.m
?????文件????????1944??2005-11-29?14:24??runCalibration.m
?????文件????????1165??2005-12-15?10:55??SLM.m
?????文件??????203573??2005-12-15?10:52??SLM.pdf
?????文件?????????527??2005-11-30?00:31??stopSoundCard.m
?????文件?????????859??2005-11-29?12:44??updateDisplay.m
?????文件?????2756318??2005-11-22?15:49??examples\trashtruck.wav
?????目錄???????????0??2005-11-22?15:49??examples\