The audio signal

Why audio signals cannotbe transmitted directly into space ?

(A): If in the presence of two independent audio signals, no beats are heard, it need not imply that they are of same frequency. (R): If the frequency difference is more than 10 Hz no beats are heared.

(A): If in the presence of two independent audio signals, no beats are heard, it need not imply that they are of same frequency. (R): If the frequency difference is more than 10 Hz no beats are heared.

For transmitting audio signal properly