Biomedical Engineering Reference
In-Depth Information
FIGURE 6-6
Audiogram showing
mild hearing loss.
The following MATLAB script plays a sequence of sounds of different frequencies in
random order. If played through an audio system with a frequency response that extends
beyond 20 kHz, it can be used as a rough method to identify hearing loss.
%hearing test
%audio tones.m
fs = 44.1e3; % Sample frequency (Hz)
duration = 5; % Duration of each tone (s)
ts = 1/fs:1/fs:duration;
window = hanning(length(ts))';
% random selection of frequencies between 0 and 22000 (Hz)
freq = [500, 1500, 14000, 2500, 0, 300, 16000, 11000, 16500, 15000, ...
17500, 20000, 14500, 13000,700, 15500, 18000, 17200, 14800, 3000, ...
4400, 0, 19000, 16800, 12000, 17500, 15800, 7000, 22000, 250];
for i = 1:length(freq)
tone = sin(2*pi*freq(i).*ts);
tone = tone.*window;
sound(tone, fs)
disp(['Playing Tone ' num2str(i)]);
pause(duration)
disp(['Complete - Press key for next tone']);
pause
end
More complicated tests include tympanometry, which determines how well sound
passes through the eardrum into the middle ear by examining sound reflection from the
eardrum at different pressures. The Rinne tuning fork test compares how well the patient
