It is not so slow

It depends on the altitude, the humidity, and the temperature of the air.
At Sea level the speed of sound is roughly 344.4 meters per second.
The speed at which sound propagates (or travels from its source) is directly influenced by both the medium through which it travels and the factors affecting the medium, such as altitude, humidity and temperature for gases like air.
It is important to note that sound speed in air is determined by the air itself. It is not dependent upon the sounds amplitude, frequency or wavelength
Hope you get the answer dear sir !!!

Most solids, liquids, and gases of ordinary experience can serve as media for sound. A mechanical disturbance may be produced in any number of ways but will consist of a sudden increase in pressure at some point. Since the material is elastic, the compression is not permanent; once the disturbing influence is removed, the compressed region will rebound, but in doing so it will compress an adjacent region. The result of this cycle repeating itself is the generation of a compression wave, followed by a rarefaction wave as each region of elastic material rebounds. These waves are longitudinal, i.e., the displacement of a particle of the medium is in the direction of wave motion (note, however, that there is no net transport of material). The waves thus generated travel through the medium at a speed that is a function of the equilibrium pressure and density of the material and, to various extents, of the specific heat (for a gas), the elasticity (for liquids and solids), and the temperatu ...more