From its roots in the sonic sociology and radio art of Schafer and his colleagues, acoustic ecology has found expression in many different fields. While most have taken some inspiration from Schafer's writings, in recent years there have also been healthy divergences from the initial ideas. Among the expanded expressions of acoustic ecology are increasing attention to the sonic impacts of road and airport construction, widespread networks of "phonographers" exploring the world through sound,[4] the broadening of bioacoustics (the use of sound by animals) to consider the subjective and objective responses of animals to human noise, including increasing use of the idea of "acoustic ecology" in the literature, and a popular in the effects of human noise on animals, with ocean noise capturing the most attention.