Hands-free telephone assembly

Claim 2

A hands-free telephone assembly comprising: a) a speech network mounted in a base unit and having an input channel and an output channel, said speech network being connected to a telephone interface which is selectively connectable to a telephone line; b) a gain-controllable amplifier in said output channel; c) a primary transducer including a speaker connected to the output of said gain-controllable amplifier, and a primary microphone; d) a gain and frequency controllable amplifier connecting the primary microphone to said input channel; e) a housing separate from the base unit and containing said primary transducer; f) said housing being constructed and arranged so as to fit the ear canal of a user and to be releasably maintained therein; and h) a cancellation mechanism for suppressing positive feedback between said primary microphone and speaker; i) wherein the microphone in said housing is unidirectional and is positioned toward the ear canal when said housing is fitted thereinto; and j) wherein the microphone in said housing is mounted on a cantilever support on the speaker in said housing, said support being of sound absorbing material.

Claim 3

A hands-free telephone assembly according to claim 1 wherein said housing includes a resilient, flexible, hollow, generally conical conduit whose narrower end is of a size to be received in the ear canal, said conduit having a plurality of circular holes whose diameter is a function of the location along the length of the conduit.

Claim 4

A hands-free telephone assembly according to claim 2 wherein the diameter of the holes near the narrower end of the conduit is smaller than the diameter of the holes remote from the narrower end of the conduit.

Claim 5

A hands-free telephone assembly comprising: a) a speech network mounted in a base unit and having an input channel and an output channel, said speech network being connected to a telephone interface which is selectively connectable to a telephone line; b) a gain-controllable amplifier in said output channel; c) a primary transducer including a speaker connected to the output of said gain-controllable amplifier, and a primary microphone; d) a gain and frequency controllable amplifier connecting the primary microphone to said input channel; e) a housing separate from the base unit and containing said primary transducer; f) said housing being constructed and arranged so as to fit the ear canal of a user and to be releasably maintained therein; and h) a cancellation mechanism for suppressing positive feedback between said primary microphone and speaker; i) wherein the microphone in said housing is unidirectional and is positioned toward the ear canal when said housing is fitted thereinto; and j) wherein the cancellation mechanism includes a second transducer in the from of a secondary microphone and a secondary speaker mounted in a second housing of a size comparable to the first mentioned housing, and a second gain and frequency controllable amplifier, and wherein said telephone includes a chamber having a geometry comparable to a human ear, said second housing being embedded in said chamber.

Claim 6

A hands-free telephone assembly comprising: a) a speech network mounted in a base unit and having an input channel and an output channel, said speech network being connected to a telephone interface which is selectively connectable to a telephone line; b) a gain-controllable amplifier in said output channel; c) a primary transducer including a speaker connected to the output of said gain-controllable amplifier, and a primary microphone; d) a gain and frequency controllable amplifier connecting the primary microphone to said input channel; e) a housing separate from the base unit and containing said primary transducer; f) said housing being constructed and arranged so as to fit the ear canal of a user and to be releasably maintained therein; and h) a cancellation mechanism for suppressing positive feedback between said primary microphone and speaker; i) wherein the microphone in said housing is unidirectional and is positioned toward the ear canal when said housing is fitted thereinto; and j) wherein the cancellation mechanism includes a second transducer in the from of a secondary microphone and a secondary speaker mounted in a second housing of a size comparable to the first mentioned housing, and a second gain and frequency controllable amplifier, and wherein said telephone includes a chamber having a geometry comparable to a human ear, said second housing being embedded in said chamber.

Claim 7

A hands-free telephone assembly according to claim 4 including: a) a differential amplifier having a pair of inputs respectively connected to the output of the two gain and frequency controllable amplifiers; and b) means connected to the output of said differential amplifier to said input channel of the speech network.

Claim 8

A hands-free telephone assembly according to claim 2 comprising: a) a speech network mounted in a base unit and having an input channel and an output channel, said speech network being connected to a telephone interface which is selectively connectable to a telephone line; b) a gain-controllable amplifier in said output channel; c) a primary transducer including a speaker connected to the output of said gain-controllable amplifier, and a primary microphone; d) a gain and frequency controllable amplifier connecting the primary microphone to said input channel; e) a housing separate from the base unit and containing said primary transducer; f) said housing being constructed and arranged so as to fit the ear canal of a user and to be releasably maintained therein; and h) a cancellation mechanism for suppressing positive feedback between said primary microphone and speaker; i) wherein the microphone in said housing is unidirectional and is positioned toward the ear canal when said housing is fitted thereinto; and j) wherein said cancellation mechanism includes a secondary microphone mounted in said housing such that the secondary microphone is positioned behind the primary speaker.

Claim 9

A hands-free telephone assembly according to claim 6 wherein each microphone is physically attached to the housing of the speaker by a sound absorbing column.