Humans can hear sound waves with frequencies in the range of 20 Hz to 20,000 Hz (20 kHz). The wave speed of sound in air at room temperature (20 degrees Celsius) is approximately 343 meters per second (m/s). So, the wave speeds that humans can hear are those which frequencies in the range of 20 Hertz - 20,000 Hz, and wave speeds of approximately 343 m/s.