Earpiece, telephone handset and headphone intended to correct individual hearing deficiencies

A self-contained and individualized telephone handset comprising a direct current source and detachable means for connecting said handset with a telephone apparatus, wherein said handset comprises one adjustable pass-band filter and two potentiometers, the pass-band of said filter having a central frequency and a width adjustable independently of each other by means of said two potentiometers, said pass-band filter being connected on an earpiece of said telephone handset and each of said two potentiometers being equipped with a knurl so that a user of said handset may vary the width and the central frequency of the pass-band independently of each other to adapt this pass-band to his proper hearing deficiencies.

A self-contained and individualized telephone handset comprising a direct current source and detachable means for connecting said handset with a telephone apparatus wherein an earpiece of said handset comprises an adjustable pass-band filter, the pass-band thereon having a central frequency and a width adjustable independently of each other, said pass-band filter comprising integrated circuits forming electronic switches which have a control electrode and a resistance which depends on a cyclic ratio of a train of rectangular pulses at constant frequency applied on said gate, and further comprising two means for producing two trains of rectangular pulses each having a cyclic ratio adjustable by a potentiometer having a knurl, said producing means being connected to said control electrodes of said electronic switches, so that a user of said telephone handset can adapt said earpiece to his hearing deficiencies by turning said two knurls which enable the resistances of said switches to be varied and consequently the central frequency and the width of said pass-filter to be varied independently of each other.

A self-contained and individualized telephone handset comprising an earpiece, a microphone, a direct current source and detachable means for connecting said handset with a telephone apparatus, wherein said earpiece comprises one adjustable pass-band filter and two potentiometers, the pass-band of said filter having a central frequency and a width adjustable independently of each other by means of said two potentiometers, said pass-band filter being connected to said earpiece and each of said two potentiometers being equipped with a knurl so that a user of said handset may vary the width and the central frequency of the pass-band independently of each other to adapt this pass-band to his proper hearing deficiencies.

A self-contained and individualized telephone handset comprising an earpiece, a microphone, a direct current source and detachable means for connecting said handset with a telephone apparatus, wherein said earpiece comprises an adjustable pass-band filter the pass-band thereof having a central frequency and a width adjustable independently of each other, said pass-band filter comprising integrated circuits forming electronic switches which have a control electrode, and a resistance which depends on a cyclic ratio of a train of rectangular pulses at constant frequency applied on said control electrode, and further comprising means for producing two trains of rectangular pulses each having a variable cyclic ratio adjustable by a potentiometer having a knurl, said producing means being connected on said control electrode so that a user adapting the telephone handset to his hearing deficiencies turns said knurls to vary the cyclic ratio of said trains of rectangular pulses, so as to vary the effective resistances of said electronic switches, enabling said central frequency and said width to be varied independently of each other.