A plurality of carrier signals are modulated by pulses corresponding to signals in audio frequency bands. The carrier signals are transmitted to a receiver having independent channels for receiving and demodulating the transmitted signals. The detected pulses are applied to electrodes on a prosthetic device implanted in the cochlea with the electrodes selectively positioned in the cochlea to stimulate regions having a desired frequency response. The pulses have a frequency which corresponds to the frequency of signals in an audio band and a pulse width which corresponds to the amplitude of signals in the audio band.

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. Signals may also be provided to identify that spoken words such as "paragraph" or "comma" are actually directions controlling the form, rather than the content, of the speech by the speaker. The selected signals, the identifying or classifying signals and the signals representing directions may be recovered by the system of this invention. The selected and identifying signals may be processed to detect syllables of speech and the syllables may be classified into phrases or sentences. The result may then be converted to a printed form representing the speech or utilized in the operation of another device.

A method and apparatus for indicating emotional stress in speech by normalizing the ratio of peak amplitude signals in two or more frequency regions of a single response. Normalization is achieved by comparing all subsequent ratios with a selected stored ratio of the same speaker.

An apparatus for the detection of malformations and for orthophonic reeducation by visual control of nasal breathing and of speech sounds in a human subject. A housing has two conduits so spaced and oriented as to be adapted to be brought into juxtaposition with the nostrils of a human subject. A thermistor is disposed in each conduit. A microphone is so disposed in the housing as to face the mouth of a human subject when the conduits are juxtaposed with the nostrils of the same human subject. Signals from said thermistors and the amplitude of sounds received by the microphone are measured and separately displayed.

A small diameter rolled up electrode array for implantation in the cochlea is provided herein. The array includes a flexible, biologically-inert planar support member which has been rolled up to a cylindrical shape to have a proximal end and a distal end. A plurality of electrodes is located at predetermined, spaced distances along a portion of the length of the rolled up, cylindrically-shaped support member starting at the proximal end, each of the electrodes comprising an open ended ring almost encircling the support member and a conducting feedline monolithically associated with each electrode, such feedline lying on the outer surface of the rolled up curved outer surface of the rolled up cylindrical support member, and extending from each associated electrode to the distal end thereof. The support member is thus being rolled up into a cylindrical shape to facilitate insertion of the electrode array into the cochlea while minimizing trauma during the insertion procedure.