This paper is from the proceedings of a second international conference on noise as a public health hazard. Funded by the Office of Noise Abatement and Control of the Environmental Protection Agency, these conference proceedings serve as a source material summarizing all known criteria that could be used in establishing national standards for noise control. The conference limited content to the effects of noise on health, thus eliminating discussions of a technical engineering or legal nature. Numerous topics discussed at the conference include: noise-induced hearing loss; community response; and sleep disturbance due to noise. The paper presented here concerns noise and its effect on the hearing of speech. In this research, the author reports that the speech interference level depends upon a number of varying factors. Among these are the octaves chosen for speech communication, the types of speech discrimination tests used, and the wearing of ear plugs or muffs by normal and hearing loss subjects. (MA)