Precision automatic audiometer

Claim 2

An audiometer apparatus comprising, in combination: a. an audiometric patient test station having right and left earphones and a two position patient actuated switch; b. programmably controllable right-left earphone switching means connected to receive an audio signal and selectively direct the same to the right or left earphone at said station; c. a programmably controllable signal source adapted to provide in some predetermined order a series of continuous tone signals arranged in a fixed repeatable sequence, each tone signal in the series being oF a selected audio frequency, amplitude and period of duration; d. a programmably controllable continuous control voltage source productive of a ramp voltage wave controllable as to ascending and descending direction and representing a control voltage having maximum and minimum values when moved without interruption in either direction, said control voltage source being connected to said two position switch and being adapted such that the direction of said ramp voltage wave may be interrupted and reversed in direction by the position of said two position switch and the magnitude of the ramp voltage wave may be regulated in coordination with desired maximum and minimum audio thresholds in said earphones; e. programmably controllable circuit attenuator means connected to said signal source to receive said tone signals and to said control voltage source to receive said ramp voltage wave, said attenuator means being adapted to generate therefrom an audio output test signal having precisely controlled gain qualities in linear proportion to said control voltage and at the selected said frequency, said earphone switching means being connected to receive said test signal; f. preprogrammed control logic circuit means connected to programmably control said signal source, voltage source and earphone switching means whereby upon actuation thereof said signal and voltage source are energized to produce said tone signals and voltage wave wherein said patient hears first in one said earphone and then the other said series of signals and during the hearing of each tone signal in each respective earphone the subject is enabled to move said two position switch to a first position when said tone signal is first heard and to a second position when said tone signal is lost to hearing and by so positioning said two position switch said subject being able to control both the direction of said voltage wave and the maximum or minimum level achieved in each direction; and g. recording means connected to said voltage source and adapted to develop and record a printout for said patient in a form directly corresponding to the earphone levels heard as determined by when and at what amplification levels the patient operates said two position switch in respect to said tone signals as an indication of the patient''s hearing loss.

Claim 3

An audiometer as claimed in claim 1 including a tone interrupter circuit means connected to interrupt and convert said continuous tone signals into pulse form.

Claim 4

An audiometer as claimed in claim 1 wherein said control logic circuit includes manually operated reset circuitry means adapted to cause said tone signal sequence to be reset to a predetermined starting frequency.

Claim 5

In an audiometer as claimed in claim 1 wherein said right-left earphone switching means, said signal source, said voltage source, said attenuator means and said logic circuit means comprise solid state components thereby adapting the same to function without mechanical motion.

Claim 6

In an audiometer as claimed in claim 1 wherein said signal source comprises a voltage controlled oscillator and said logic circuit means precisely controls the amount of voltage supplied said oscillator to control said tone signal frequency.

Claim 7

In an audiometer as claimed in claim 1 wherein said circuit attenuator means incorporates circuitry for computing a signal representing the logarithm of said tone signal, for combining such logarithm signal and said ramp voltage wave, to produce the antilog of such combination and from such antilog to produce said test signal.

Claim 8

In an audiometer as claimed in claim 1 including manually actuated holding circuitry means adapted when actuated to cause said logic circuit means to stop and hold said tone signal sequence at the then programmed frequency.

Claim 9

In an audiometer as claimed in claim 1 wherein said logic circuit means is programmed to cause said tone signal sequence to be heard first in one of said earphones and then in the other of said earphones and with a redundant test tone in the latter.

Claim 10

In an audiometer as claimed in claim 1 wherein said logic circuit means includes cross talk circuit means connected to said earphones and adapted to selectively prevent one of said earphones from conducting a signal when the other of said earphones is being utilized for testing.

Claim 11

In an audiometer as claimed in claim 1 including ramp voltage wave conditioning circuit means adapted to cause the instantaneous slope of said ramp voltage wave to be steep at the onset of each said tone signal presentation and to continuously decrease said ramp voltage slope to a relatively gradual slope at the conclusion of each said tone signal.

Claim 12

In an audiometer as claimed in claim 1 wherein said printout is in the nature of a voltage envelope and said recording means is a strip chart recorder adapted to print said envelope.

Claim 13

In an audiometer as claimed in claim 1 wherein said printout is in the form of numeric data and said recording means is a printer adapted to print such numeric date.

Claim 14

In an audiometer as claimed in claim 1 including hearing threshold level compensation circuit means connected to receive the output of said voltage source and to electrically compensate said voltage source for normal ear efficiencies and earphone deficiencies to provide an electrical output corrected for both.

Claim 15

In an audiometer system, the method of generating and recording audiometric data for a patient, comprising the steps: a. establishing for the patient an audiometric patient test station having right and left earphones and a two position patient actuated switch; b. directing to the station under logic circuit program control and in some predetermined order a series of continuous tone signals arranged in a fixed repeatable sequence, each tone signal in the series being of a selected audio frequency, amplitude and period of duration; c. establishing for the station a programmably controllable continuous control voltage source productive of a ramp voltage wave controllable as to ascending and descending direction and representing a control voltage having maximum and minimum values when moved without interruption in either direction and connecting said control voltage source to the said two position switch such that the direction of said ramp voltage wave may be interrupted and reversed in direction by the position of said two position switch at the test station and the magnitude of the ramp voltage wave may be regulated in coordination with the patient''s thresholds in said earphones; d. connecting a programmably controllable circuit attenuator means for the test station to said signal source to receive said tone signals and to said control voltage source to receive said ramp voltage wave and generating for the test station an audio output test signal having precisely controlled gain qualities in linear proportion to said control voltage and at the selected said frequency; e. directing said test signal for the test station through programmably controllable right-left earphone switching means and programmably controlling said signal source, voltage source and earphone switching means for the test station with said logic circuit whereby upon local manual actuation of the test station, said signal and voltage sources for the test station produce said tone signals and voltage wave and said earphone switching means switches under said logic circuit supervision wherein said patient at each such test station hears first in one said earphone and then in the other said series of signals and during the hearing of each tone signal in each respective earphone the patient is enabled to move said two position switch to a first position when said tone signal is first heard and to a second position when said tone signal is lost to hearing and by so positioning said two position switch said patient is able to control both the direction of said voltage wave and the level achieved in each direction; g. developing with voltage developing means connected to each respective said voltage source a voltage envelope for the patient which envelope directly corresponds to the earphone levels heard as determined by when and at what audio levels the said patient operates said two position switch; and h. recording said envelope for the said patient in correspondence with the earphone levels heard by the patient as determined by when and at what amplification levels the patient operates said two position switch in respect to said tone signals as an indication of the patient''s hearing loss.

Claim 16

In an audiometer system, the method of generating and recording audiometric data for a patient, comprising the steps: a. establishing for the patient an audiometric patient test station having right and left earphones and a two position patient actuated switch; b. directing to the station under logic circuit program control and in some predetermined order a series of continuous tone signals arranged in a fixed repeatable sequence, each tone signal in the series being of a selected audio frequency, amplitude and period of duration; c. establishing for the station a programmably controllable continuous control voltage source productive of a ramp voltage wave controllable as to ascending and descending direction and representing a control voltage having maximum and minimum values when moved without interruption in either direction and connecting said control voltage source to the said two position switch such that the direction of said ramp voltage wave may be interrupted and reversed in direction by the position of said two position switch at the test station and the magnitude of the ramp voltage wave may be regulated in coordination with the patient''s thresholds in said earphones; d. connecting a programmably controllable circuit attenuator means for the test station to said signal source to receive said tone signals and to said control voltage source to receive said ramp voltage wave and generating for the test station an audio output test signal having precisely controlled gain qualities in linear proportion to said control voltage and at the selected said frequency; e. directing said test signal for the test station through programmably controllable right-left earphone switching means and programmably controlling said signal source, voltage source and earphone switching means for the test station with said logic circuit whereby upon local manual actuation of the test station, said signal and voltage sources for the test station produce said tone signals and voltage wave and said earphone switching means switches under said logic circuit supervision wherein said patient at each such test station hears first in one said earphone and then in the other said series of signals and during the hearing of each tone signal in each respective earphone the patient is enabled to move said two position switch to a first position when said tone signal is first heard and to a second position when said tone signal is lost to hearing and by so positioning said two position switch said patient is able to control both the direction of said voltage wave and the level achieved in each direction; g. developing with voltage developing means connected to each respective said voltage source a voltage envelope for the patient which envelope directly corresponds to the earphone levels heard as determined by when and at what audio levels the said patient operates said two position switch; and h. recording said envelope for the said patient in correspondence with the earphone levels heard by the patient as determined by when and at what amplification levels the patient operates said two position switch in respect to said tone signals as an indication of the patient''s hearing loss.

Claim 17

The method of claim 14 including the step of generating said tone signals in pulse form.

Claim 18

The method of claim 15 including the step of changing the instantaneous slope of ramp voltage during each tone signal presentation from a relatively steep slope at the onset of each said tone signal and continuously decreasing said slope to a relatively gradual slope at the conclusion of each said tone signal presentation.

Claim 19

The method of claim 14 wherein said recording comprises chart strip recording.

Claim 20

The method of claim 14 wherein said recording comprises electrically converting said envelope to numeric data and recording as a numeric printout.

Claim 21

The method of claim 14 including the step of electrically compensating the output of said voltage source for normal ear efficiencies and earphone deficiencies.

Claim 22

An audiometer apparatus comprising, in combination; a. an audiometric patient test station having right and left earphones and a two position patient actuated switch; b. programmably controllable solid state right-left earphone switching means connected to receive an audio signal and selectively direct the same to the right or left earphone at said station; c. a programmably controllable solid state voltage controlled oscillator signal source adapted to provide in some predetermined order a series of continuous tone signals arranged in a fixed repeatable sequence, each tone signal in the series being of a selected audio frequency, amplitude and period of duration; d. a programmably controllable continuous control solid state voltage source productive of a ramp voltage wave controllable as to ascending and descending direction and representing a control voltage having maximum and minimum values when moved without interruption in either direction, said control voltage source being connected to said two position switch and being adapted such that the direction of said ramp voltage wave may be interrupted and reversed in direction by the position of said two position switch and the magnitude of the ramp voltage wave may be regulated in coordination with desired maximum and minimum audio thresholds in said earphones; e. programmably controllable solid state circuit attenuator means connected to said signal source to receive said tone signals and to said control voltage source to receive said ramp voltage wave, said attenuator means being adapted to generate therefrom an audio output test signal having precisely controlled gain qualities in linear proportion to said control voltage and at the selected said frequency, said circuit attenuator means incorporating circuitry for computing a signal representing the logarithm of said tone signal, for combining such logarithm signal and said ramp voltage wave, to produce the antilog of such combination and from such antilog to produce said test signal, said earphone switching means being connected to receive said test signal; f. preprogrammed control solid state logic circuit means connected to programmably control said signal source by precisely controlling the voltage supplied said oscillator to control said tone signal frequency, voltage source and earphone switching means whereby upon actuation thereof said signal and voltage source are energized under program control to produce said tone signals and voltage wave wherein said patient hears first in one said earphone and then the other, said series of signals and during The hearing of each tone signal in each respective earphone the subject is enabled to move said two position switch to a first position when said tone signal is first heard and to a second position when said tone signal is lost to hearing and by so positioning said two position switch said subject being able to control both the direction of said voltage wave and the maximum or minimum level achieved in each direction, said control logic circuit including manually operated reset circuitry means adapted to cause said tone signal sequence to be reset to a predetermined starting frequency, and including cross talk circuit means connected to said earphones and adapted to selectively prevent one of said earphones from conducting a signal when the other of said earphones is being utilized for testing. g. tone interrupter circuit means connected to interrupt and convert said continuous tone signals into pulse form; h. manually actuated holding circuitry means adapted when actuated to cause said logic circuit means to stop and hold said tone signal sequence at the then programmed frequency; i. hearing threshold level compensation circuit means connected to receive the output of said voltage source and to electrically compensate said voltage source for normal ear efficiencies and earphone deficiencies to provide an electrical output corrected for both; and j. recording means connected to said voltage source and adapted to develop and record a voltage envelope for said patient directly corresponding to the earphone levels heard as determined by when and at what amplification levels the patient operates said two position switch in respect to said tone signals as an indication of the patient''s hearing loss.

Claim 23

An audiometer apparatus comprising, in combination; a. an audiometric patient test station having right and left earphones and a two position patient actuated switch; b. programmably controllable solid state right-left earphone switching means connected to receive an audio signal and selectively direct the same to the right or left earphone at said station; c. a programmably controllable solid state voltage controlled oscillator signal source adapted to provide in some predetermined order a series of continuous tone signals arranged in a fixed repeatable sequence, each tone signal in the series being of a selected audio frequency, amplitude and period of duration; d. a programmably controllable continuous control solid state voltage source productive of a ramp voltage wave controllable as to ascending and descending direction and representing a control voltage having maximum and minimum values when moved without interruption in either direction, said control voltage source being connected to said two position switch and being adapted such that the direction of said ramp voltage wave may be interrupted and reversed in direction by the position of said two position switch and the magnitude of the ramp voltage wave may be regulated in coordination with desired maximum and minimum audio thresholds in said earphones; e. programmably controllable solid state circuit attenuator means connected to said signal source to receive said tone signals and to said control voltage source to receive said ramp voltage wave, said attenuator means being adapted to generate therefrom an audio output test signal having precisely controlled gain qualities in linear proportion to said control voltage and at the selected said frequency, said circuit attenuator means incorporating circuitry for computing a signal representing the logarithm of said tone signal, for combining such logarithm signal and said ramp voltage wave, to produce the antilog of such combination and from such antilog to produce said test signal, said earphone switching means being connected to receive said test signal; f. preprogrammed control solid state logic circuit means connected to programmably control said signal source by precisely controlling the voltage supplied said oscillator to control said tone signal frequency, voltage source and earphone switching means whereby upon actuation thereof said signal and voltage source are energized under program control to produce said tone signals and voltage wave wherein said patient hears first in one said earphone and then the other, said series of signals and during The hearing of each tone signal in each respective earphone the subject is enabled to move said two position switch to a first position when said tone signal is first heard and to a second position when said tone signal is lost to hearing and by so positioning said two position switch said subject being able to control both the direction of said voltage wave and the maximum or minimum level achieved in each direction, said control logic circuit including manually operated reset circuitry means adapted to cause said tone signal sequence to be reset to a predetermined starting frequency, and including cross talk circuit means connected to said earphones and adapted to selectively prevent one of said earphones from conducting a signal when the other of said earphones is being utilized for testing. g. tone interrupter circuit means connected to interrupt and convert said continuous tone signals into pulse form; h. manually actuated holding circuitry means adapted when actuated to cause said logic circuit means to stop and hold said tone signal sequence at the then programmed frequency; i. hearing threshold level compensation circuit means connected to receive the output of said voltage source and to electrically compensate said voltage source for normal ear efficiencies and earphone deficiencies to provide an electrical output corrected for both; and j. recording means connected to said voltage source and adapted to develop and record a voltage envelope for said patient directly corresponding to the earphone levels heard as determined by when and at what amplification levels the patient operates said two position switch in respect to said tone signals as an indication of the patient''s hearing loss.