Abstract: A micro-receiver for receiving a high frequency frequency modulated or phase modulated signal, including a single integrated circuit in BiCMOS technology and on which is integrated a high frequency amplifier, an oscillator, a modulator, an intermediate frequency filter, an intermediate frequency amplifier, a demodulator, a low pass filter and a low frequency amplifier. The integrated circuit includes in addition a muting or squelch circuit, a voltage multiplier as well as a standby circuit. The circuits working in a lower frequency range are implemented in CMOS technology, and operated in a very energy-saving way with a single-cell battery with a low battery voltage of 1.3 V. The voltage multiplier provides a higher operating voltage for the circuits working in a higher frequency range.

Abstract: For hearing aids to be worn in the ear initially the measurements of the inner space of the ear are determined by a laser apparatus and the measurement are stored in a computer. The computer controls a milling cutter on which a blank consisting of plastic material into which all necessary components, such as electronic amplifier and sound transducer have been molded is shaped by means of a milling operation to provide a shape corresponding precisely to the inner space of the ear. The method eliminates the time consuming work for the production of a mold and the purchaser can obtain immediately a precisely fitting hearing aid.