A typical audio frequency of 3000 Hz will have a wavelength of 100 km and would need an effective antenna length of 25 km! By comparison, a typical carrier for FM is 100 MHz, with a wavelength of 3 m, and could use an antenna only 80 cm long.

Question

anonymous · Answer

Well, no doubt, but audio frequencies are almost never used in radio  transmission, except for some odd usages by the military e.g. to communicate with submarines.  Audio frequencies are usually transmitted through the air, as sound waves, and in that case their wavelength is appropriate to the ear, a few centimeters.

anonymous · Answer

The following text is written in your website:
“”To reduce the wavelength for efficient transmission and reception (the optimum antenna size is ½ or ¼ of a wavelength). A typical audio frequency of 3000 Hz will have a wavelength of 100 km and would need an effective antenna length of 25 km.’’
You are transmitting an low frequency audio signal (3000 Hz), while you are considering the velocity of light as its traveling speed. Hence calculated the antenna height as 25 km. The velocity of light only be considered in case of electromagnetic wave. You guys are totally funny, giving others totally a wrong teaching.