Abstract: The present invention processes an independent body of speech during an enrollment process and creates a set of speaker specific enrollment parameters for normalizing analysis parameters including the speaker's pitch, the frequency spectrum of the speech as a function of time, and certain measurements of the speech signal in the time-domain. A particular objective of the invention is to make these analysis parameters have the same meaning from speaker to speaker. Thus after the pre-processing performed by this invention, the parameters would look much the same for the same word independent of speaker. In this manner, variations in the speech signal caused by the physical makeup of a speaker's throat, mouth, lips, teeth, and nasal cavity would be, at least in part, reduced by the pre-processing.

Abstract: The present invention is directed to an apparatus and method which provide repeatable control of speech input to a microphone via audio feedback to a user. In this manner, repeatable and simultaneous control of microphone positioning and speaking volume is obtained. In a first embodiment, a microphone in the mouthpiece of the handset is used to detect sounds emanating from the mouth and audio feedback is provided through a speaker in the handset earpiece to ensure the microphone is positioned correctly for the application. In alternate embodiments, feedback is provided based upon voiced and unvoiced amplitudes of the input speech to obtain more optimal results.

Abstract: A plurality of microphones are disposed on a body to detect the speech of a speaker. First, second and third microphones may respectively detect the sounds emanating from the speaker's mouth, nose and throat and produce signals representing such sounds. A fourth microphone may detect the fricative and plosive sounds emanating from the speaker's mouth and produce signals representing such sounds. The signals from the different microphones are compared to allow the discrimination of certain speech sounds. For example, a high amplitude of the signal from the nose microphone relative to that from the mouth microphone indicates that a nasal sound such as m, n, or ng was spoken. Identifying signals are provided to the speech recognition system to aid in identifying the speech sounds at each instance. The identifying signals can also select a microphone whose signal can be passed on to the recognition system in its entirety.