Contents

Tokyo Impulses Responses - Comparison of the delay times

clear all
close all

in_path = '~/yamaha/recordings/Tokyo_03Jul06/processed/sinesweep/';
global_name = 'sinesweep';
mics = {'01pzm1', '02pzm2', '03pzm3', '04pzm4'...
    '05dir1', '06dir1', '07dir1', '08dir1', '09dirup', '10sourcemic'};
spots = {'ins','adj'};
cfile = '~/yamaha/test_sounds/ssBCE479C5.wav';
eta = 18;

[IRS,fs] = irgen(in_path,global_name,mics,spots,cfile,eta);
Nspots = size(IRS,1);
Nmics = size(IRS,2);
ntaps = fs;

time = (0:ntaps-1)/fs*1000;
for index_spots = 1:1
  figure;
  for index_mics = 1:4
    %subplot(4,1,index_mics)
    impulses(index_mics,:) = IRS(index_spots,index_mics).ir(1:ntaps);

    %maximu absolute value of the impulse response
    maximp = max(abs(impulses(index_mics,:)));

    %find the index where the impulse response starts
    %the threshold is .01*max(abs(impulse))
    istart(index_mics) = find(abs(impulses(index_mics,:)) > ...
			      0.04*maximp,1);
    istart(index_mics) = (istart(index_mics)-1)/fs*1000; %in ms
  end
  plot(time,impulses'+ones(ntaps,1)*[0:3]*2*maximp)
  hold on;
  plot(istart,[0:3]*2*maximp,'o','LineWidth',4,'Color','k')
  legend('pzm1','pzm2','pzm3','pzm4')
  grid
end

V = axis;
axis([0 15 V(3:4)])
xlabel('Time (ms)')
title({'Impulse responses of the four PZM microphones - Tokyo office';...
       'Source in the Adjacent Room'})

Impulse Response for spot: ins and mic: 01pzm1 GENERATED
Impulse Response for spot: ins and mic: 02pzm2 GENERATED
Impulse Response for spot: ins and mic: 03pzm3 GENERATED
Impulse Response for spot: ins and mic: 04pzm4 GENERATED
Impulse Response for spot: ins and mic: 05dir1 GENERATED
Impulse Response for spot: ins and mic: 06dir1 GENERATED
Impulse Response for spot: ins and mic: 07dir1 GENERATED
Impulse Response for spot: ins and mic: 08dir1 GENERATED
Impulse Response for spot: ins and mic: 09dirup GENERATED
Impulse Response for spot: ins and mic: 10sourcemic GENERATED
Impulse Response for spot: adj and mic: 01pzm1 GENERATED
Impulse Response for spot: adj and mic: 02pzm2 GENERATED
Impulse Response for spot: adj and mic: 03pzm3 GENERATED
Impulse Response for spot: adj and mic: 04pzm4 GENERATED
Impulse Response for spot: adj and mic: 05dir1 GENERATED
Impulse Response for spot: adj and mic: 06dir1 GENERATED
Impulse Response for spot: adj and mic: 07dir1 GENERATED
Impulse Response for spot: adj and mic: 08dir1 GENERATED
Impulse Response for spot: adj and mic: 09dirup GENERATED
Impulse Response for spot: adj and mic: 10sourcemic GENERATED

Comments

We see that the PZM 4 (The one in the wall separating the rooms from the source) is the one that recieves the signal first. I know that the PZM is supose to be hemispherical, but this still seems to work.

Published with MATLAB® 7.1