A high-quality all-digital sound spectrograph developed for speech signal analysis

A new sound spectrograph has been developed to provide analysis facilities well beyond the capability of previously available instruments. The equipment is all-digital in operation, using high-speed signal processing modules under microprocessor control. It has thus been possible to provide a wide variety of analysis options, and to incorporate a keyboard and an alphanumeric display for easy interaction with users. Particular advantages of this approach include the ability to achieve any desired dynamic range of marking (maximum>60 dB), and any desired scales of both time and frequency. Experience in use has shown the value of some very unusual analysis conditions, such as wide-band speech spectrograms with a grossly expanded time scale to show detailed short-term spectrum variations throughout each glottal cycle.