ABSTRACT
Spectrography is the most important technique available to the experimental phonetician, and the visual images which it produces, known as spectrograms, are the visual images most often associated with experimental phonetic research. The purpose of this chapter is to introduce spectrography and related techniques for analysing sound. A good system for recording and reproducing sound is characterised by high fidelity. It is very difficult to determine the spectra of speech sounds exactly, but it is much easier to test for the presence of sine wave components within particular frequency bands. Devices which do this are known as filters, more specifically bandpass filters. Pre-emphasis is characteristic of speech generally that the lower frequencies are stronger than the higher frequencies. The practical consequence of this is that higher frequency components may be weak or even invisible on a spectrogram. The great advantage of spectrography is its ability to provide a three dimensional display on a two-dimensional surface.
