Produce sound from 1 Hz to 1000hz

Hello Everyone! How can I produce sound from 1 Hz to 1000 Hz for a duration of 20 secs? I'm using the following code for the generation of sound for 100Hz.

amp=0.5; 
fs=20500;  % sampling frequency
filename = 'CampbellAudio.wav';
duration=20;
freq=100;  %I want the frequency here to be from 1 to 1000
values=0:1/fs:duration;
a=amp*sin(2*pi* freq*values);
sound(a)
audiowrite(filename,a,fs);

Answer 1

[Walter Roberson]

http://uk.mathworks.com/matlabcentral/answers/239478-i-always-get-too-many-input-arguments-what-could-be-the-problem#answer_191289

Answer 2

[Image Analyst]

Do you have the Signal Processing Toolbox?

y = chirp(t,f0,t1,f1) generates samples of a linear swept-frequency cosine signal at the time instances defined in array t, where f0 is the instantaneous frequency at time 0, and f1 is the instantaneous frequency at time t1. f0 and f1 are both in hertz. If unspecified, f0 is e-6 for logarithmic chirp and 0 for all other methods, t1 is 1, and f1 is 100.

[Karthik Brs]

Thanks a lot for the answer! Yes, I do have the Signal processing toolbox. I have an array containing the values of 'Sound powers' at these frequencies(1-1000Hz). Is there a way wherein I can use values of sound powers as amplitudes to generate sound at these frequencies?

[Image Analyst]

Yes, you'd have to create the chirp first, then multiply by the amplitude vector element-by-element.

[Image Analyst]

I don't know what instantaneous means in this context. Do you want to plot it immediately after every element is assigned?

[Nneka Onubogu]

Thanks for your reply. I actually want the modulation frequency (fpump) to change after a particular time, lets say after every 5 secs. And i also want to plot the time domain of the signal at every frequency