The paper discusses the background of the problem of signal and noise in the seismic process, and the application of the principles of communication theory to this problem. The limitations of the seismic process are discussed along with the types of noises involved, the methods of rejecting noise, the use of filters to reduce noise, characteristics of filters, and the relationships between frequency domain, time domain, mathematical, and digital filters. In the discussion of the electronic data processing of seismic information, the characteristics of an ideal seismic digital computer system are developed in relation to the characteristics of seismic data. The choice between digital and analog field recording is discussed in relation to the needs of the seismic process and the quality of the seismic data. Among the mathematical processes discussed are velocity filtering and a number of types of Wiener filtering, including horizontal stacking, deghosting, deconvolution, and multitrace digital filtering.