How do i read audio and include it in my function?

i need to plot a graph that shows

y=y1+1×r(t)

𝑦1=sin(2𝜋𝑓𝑡+𝜋/4)

r(t): read from audio file

but my problem is i don't know include the r(t) into my program.

the program i know so far is

fs=1000;
t=0:1/fs:1;
f=440;

y=y1+1*rt
y1=sin(2*pi*f*t+pi/4);
sound(y,fs)

N=1+0.1*fs;
n=1:N;
plot(t(n),y(n))
xlabel('Time(s)')
ylabel('Amplitude')

Answer 1

[Nora Khaled]

check out this function

[y,Fs] = audioread(filename)

it reads data from the file named filename, and returns sampled data, y, and a sample rate for that data, Fs.