Abstract: A headset-based hearing tester and hearing aid programming instrument featuring an electronic module shaped as a headband having a connected acoustic transducer module. The electronic module includes microcontroller, internal and plug-in external memory for storage of program code and patient data. The headset instrument in conjunction with a hand-held patient response device is capable of automatic hearing testing. The produced audio stimuli including test tones, speech and verbal instructions are retrieved from external memory cards. The instrument automatically computes fitting parameters and is capable of programming a programmable hearing aid via a port for direct wire programming or via wireless methods including inductive coil coupling to a hearing aid equipped with a receiving coil.

Abstract: A probe microphone comprising an acoustic transducer with a cavity, to which a probe tube and a matching tube are connected. The matching tube is divided into several small tubes of a total internal transverse cross sectional area substantially corresponding to the internal transverse cross sectional area of the probe tube. The small matching tubes improve the frequency response because of their acoustic loss. Moreover, a further improvement is achieved when the matching tubes are of different lengths, the already reflected signals thereby outbalancing each other. As a result, a probe microphone with a more uniform frequency response than previously known is achieved.

Abstract: A method and apparatus for screening the hearing of a young child are disclosed. The method comprises providing, outside the field of view, a series of natural sound stimuli, which are controlled in intensity and spectrum, in various frequency bands and recording, within a time interval after each stimulus, the assessment, given by a researcher, of the response of the child, and testing the response on the basis of pass/fail criteria. The intensity and spectrum of the subsequent sound stimuli in the same or in another frequency band are determined on the basis of the result of each response test. The sound stimuli mentioned are based on processed sound signals derived from the environment. The sound stimuli are presented according to an adaptive protocol program, each response test codetermining the course of the screening. The apparatus includes at least one loudspeaker for emitting the sound stimuli and a processing and control unit.

Abstract: An apparatus for and method of applying a selected range of high frequency acoustic energy to the apical end of the eardrum of an ear canal at a predetermined, substantially absolute sound pressure level at any frequency in the range of interest. The selected range of frequencies is generated at a location remote from the ear canal and the sound pressure level of each frequency is varied at the time of generation in accordance with a calibration function to ensure the frequencies reaching the apical end of the eardrum are at the predetermined sound pressure level.The calibration function is calculated by transmitting an acoustic pulse of broad frequency spectrum into the ear canal, measuring the sound pressure of the transmitted acoustic pulse and reflection thereof adjacent the entrance of the ear canal, and removing from the spectrum of the measured sound pressure the destructive interference effects between the transmitted and reflected acoustic pulses.

Abstract: A probe is inserted into an external auditory meatus; the internal pressure of the external auditory meatus is maintained at the predetermined pressure by supplying the air from an air pump connected to one of the sound induction hole; an oscillation signal within the audible range converted into a sound with a predetermined sound pressure is transmitted into the external auditory meatus through another sound induction hole of said probe; and the change in the sound pressure within the external auditory meatus is measured through a microphone. Said probe is to be formed of a hard and relatively thick material and as small as possible in length.

Abstract: Disclosed is an apparatus for checking audio signal processing systems. The apparatus has the following features:the apparatus is provided with a first input connection, to which the input signal of the audio processing system to be checked is transmitted, a second input connection, to which the output signal of said system is transmitted, and a signal processor.

Abstract: A calibration device for an auditory prosthesis, such as a hearing aid, and an auditory prosthesis which contains such a calibration device. The calibration device comprises memory in which is stored information which is characteristic of information intrinsic to the invididual auditory prosthesis, the information being either information which represents a sufficient set of adjustment parameters required to calculate the transfer function of the auditory prosthesis or manufcturing information and a mechanism by which this information may be utilized by the auditory prosthesis or by the programming system of such auditory prosthesis.

Abstract: A programmable hearing aid has a serial data interface for receiving data transmissions, a decoder for decoding data transmissions, a program memory which stores program data values received via the serial interface, and read control logic that transmits the program data stored in the program memory when the decoder detects the receipt of a predefined read signal. Programming begins with the sending a set of program data values to the programmable hearing aid, preceded by a predefined write signal. The hearing aid automatically mutes or inhibits its operation upon receiving the write signal. A first checksum value corresponding to the program data values sent to the programmable hearing aid is calculated. Next, the data stored in the hearing aid is checked by sending a predefined read signal to the hearing aid, causing the hearing aid to transmitting the program data stored in its program memory.

Abstract: An electrical circuit system for measuring the acoustic admittance of the ear cavity, for use in single and multiple tone tympanometry and acoustic reflex response testing, in which the probe tone applied to the ear cavity can be varied over a wide frequency range and a wide range of admittance variation can be measured. The signal output of the system, derived from the output signal of a microphone located in the ear cavity, is a DC voltage accurately proportional to the logarithm of the measured admittance of the ear cavity. An RMS to DC converter, an error integrator and an exponential element provide a closed control loop system for a variable gain amplifier so as to maintain the microphone output signal level constant regardless of admittance variations in the ear cavity. The level of the signal applied to the probe tone driver to accomplish this is a measure of the cavity admittance.

Abstract: Means for transmitting an FM radio signal carrying an audio test signal to a preselected one of two receivers in the headset of a patient, together with FM signalling means carried by the patient to transmit signals to the audiometer indicating which of the patient's ears received the test signal to permit the patient to have virtually unlimited mobility during the testing procedure. Separate FM signal channels may be provided to permit simultaneous testing of a plurality of patients. Furthermore, if desired, a predetermined pattern of test signals may be recorded and means may be provided for automatically transmitting the test signals and recording the patient response signals, thereby permitting fully automatic testing to be conducted.

Abstract: A software model of the auditory characteristics of an auditory prosthesis is stored independently of the actual auditory prosthesis being fitted to determine the acoustic parameters to be utilized. A transfer function of the auditory characterictics of the individual auditory prosthesis to be fitted, or of an exemplary model of such an auditory prosthesis, is created, transformed into a table, or other usable form, and stored in software usable by the automated fitting program. The automated fitting program may then "test" or try by iterative process, the various settings for the acoustic parameters of the auditory prosthesis and determine accurately the results without actual resort the physical auditory prosthesis itself.

Abstract: Hearing faculty test apparatus, for use in relation to the inner ear by way of the so-called cochlear echo, repeatedly applied a linearly balanced set of acoustic stimuli to the ear, individually sums each related set of responses to the stimuli set, interrogates each sum to detect components above a predetermined threshold, and averages sums on a selective basis depend on the interrogation. Preferably sums are passed for averaging only when whooly within the threshold. Also, averaging is preferably by use of two like averagers to which accepted sums are applied in alternating manner, with the two averages being fed to a correlator.

Abstract: A host controller for producing data from a computer for a programmable filter of a hearing aid to cancel feedback in which phase shift and gain control means as adjusted by the computer to generate a feedback cancellation voltage which is supplied to the hearing aid for summation of the feedback and feedback cancellation voltages by the hearing aid and in which the summed feedback and feedback cancellation voltages are returned to the host controller for further adjustment of said phase shift and gain control means until feedback has been cancelled. The host controller then transmits to the programmable filter the phase shift and gain control data necessary to cancel feedback.

Abstract: A microprocessor-based audiometer for use with children. A color visual display unit is used to display an image digitally stored in memory or on disk drive to attract the childs attention and hold its concentration during testing.The child activates a response switch upon detecting the tones produced by audiometer to the generator. Correct responses are reinforced by progressive alteration of the displayed image to increasingly desirable states.

Abstract: An attachment device for a probe microphone adapted to be utilized in conjunction with the external ear canal of a person having an ear lobe. A housing is adapted to contain the probe microphone and secures the housing in a fixed relationship with respect to the ear lobe of the person. A probe tube is coupled to the housing and is adapted to be coupled to the probe microphone and adapted to be inserted into the external ear canal of the person. A holding mechanism is coupled to the housing and receives the probe tube and slideably secures the probe tube in a repositionably fixed relationship to the housing. In this manner the housing may be secured and positioned with respect to the ear lobe and the probe tube may be slid through the holding mechanism and positioned reliably in the external ear canal.

Abstract: A device is disclosed for holding a probe tube in the ear canal of a person's ear. The device includes two members. The first member has a clip for clipping the first member to an ear lobe, and a first magnetic member coupled to the clip. The second member has a microphone coupled to a probe tube, and a housing for holding the probe tube at fixed position relative to the housing. The microphone generates amplified signals corresponding to sound conducted by the probe tube. In addition, a second magnetic member is coupled to the housing of the second member so that the second member can be held in a selected position relative to the first member by the magnetic attraction of the first and second magnetic members. The first and second magnetic members preferably each have a flat surface which enables the relative positions of the first and second members to be adjusted both angularly and laterally.

Abstract: An interface unit for measuring instruments, such as audiometers, which are controlled by a computer, the interface unit being as cost-efficient as possible and setting minimum requirements for the computer hardware and software. This is achieved in that the lines (17 to 19) of the interface unit that are connected to the computer contain d-c isolating couplers (17.1 to 19.1) and are respectively connected with individual decoders (13 to 15) which, in turn, are connected to memories (7 to 9). Control lines lead from these memories to the measuring modules (1 to 3) of a measuring instrument. Such a measuring instrument is usable, in particular, as an audiometer or for establishing the optimum adjustment of a hearing aid to compensate certain hearing impairments.

Abstract: To provide for permanent calibration of an audiometer, for example, to hold the calibration even in case of an interruption of supply voltage, an electrically erasable programmable and reprogrammable read-only memory (EEPROM) (15) receives calibration data in a closed loop by comparing the output of a transducer (13) with the input to a measuring microphone (31), in digital form and after digitizing, with command outputs stored in a computer (22). A tone generator (11), likewise controlled by the computer, provides control frequencies via a controlled amplifier (12) to the transducer (13). The calibrating EEPROM (15) receives correction data from the computer via a data bus (29) which, in turn, controls the resistance of a switchable resistance (18, 181) to provide a correction voltage to the amplifier (12).

Abstract: A portable, hand-held tympanometer that has the capability of performing the tympanometry and of displaying and storing the test results all within the hand-held instrument. A separate unit that is not in any way attached to the tympanometer during the testing is provided to print the test results and to recharge the tympanometer battery. The tympanometer has a body portion and a head portion to which a speculum is attached, the speculum being adapted to engage the canal of the ear being examined in sealed relation thereto. A speaker in the speculum transmits acoustic signals into the ear canal and a microphone in the speculum receives the signals that are reflected back through the canal by the tympanic membrane. A pressure transducer is located in the head portion of the tympanometer, and a miniature pump located in the body portion operates to introduce a range of pressures into the ear canal while the acoustic signals are being transmitted and received.

Abstract: Audiometer apparatus comprises an electrostatic transducer having insulated electrodes for application to the skin on the head of a patient and driven by an ultrasonic frequency carrier signal generated in a series resonant circuit including the impedance of the body tissues between the electrodes, the carrier frequency being determined by the series resonant circuit. The amplitude of the carrier is modulated at an audio frequency, and operating parameters such as the magnitude of the current fed to the electrodes and the modulation frequency are controlled automatically in response to preselected values preset therein.Current and modulation frequency values are preset stepwise into a manually adjustable preselectors having detents formed by cooperating magnetic elements establishing successive rest positions corresponding to steps to which the preselector may be set.

Abstract: An artificial head acoustic measuring system includes a construction including portions configured to appear as human shoulders, head and ears on both sides of the head with auditory canals and microphones disposed in the auditory canals. The head portion comprises partial bodies corresponding to mean data of test persons with respect to dimensions and relative positions. The partial bodies comprise regular geometric bodies calibrated with respect to sound reflexion, diffraction and resonance behavior to define a reproducible artificial-head transmission function related to the outer geometric configuration of the construction.

Abstract: An audiological analyzer includes a speaker (12) for generating soundwaves, which are generated by a test pattern generator (20). A frequency/level shaper (18) is disposed between the test pattern generator (20) and the speaker (12) for determining both the level and the frequency response of a given signal. A TDS/ETC analyzer (28) is connected to a transducer (34) which is disposed adjacent the ear (14) of a patient. The analyzer (28) allows for exact inplace measurement of the medium through which the soundwaves are transmitted. This information is stored in a memory (40) in the form of a calibration response curve. This data available in order to compensate for attenuation through the medium. This compensation ensures proper sound pressure level delivery to the ear (14). In addition, the frequency/level shaper (18) has equalizers (90) and (92) disposed therein for entering a predetermined response.

Abstract: A method and apparatus for diagnosing pathologies of the ear, particularly pathologies such as otitis media, directs into the ear canal a sequence of acoustic waves covering a range of frequencies from a few hundred Hz to several kHz and determines the presence or absence of resonance when the incident and reflected waves are combined. The measurements are made without pressurizing the ear canal and it is not required that the contact between the instrument and the ear be air-tight. Accordingly, essentially no discomforture of the patient results from use of the instrument. The requisite measurements are made quickly (of the order of tens of milliseconds) and thus the distorting effects of patient movement are effectively eliminated. An improved version of the instrument is completely self-contained and hand-held and has the form of a "tee" in which the resonant frequency and amplitude are visually indicated by means of horizontally-and-vertically disposed arrays of light-emitting diodes.

Abstract: An earphone characteristic measuring device comprises an acoustic coupler having an acoustic tube simulated to an external auditory canal in which an earphone under measurement is to be inserted and an acoustic tube of a smaller diameter having an acoustic impedance of approximately 320 ohms connected to an end of the first acoustic tube, a sound source for emitting an impulse sound to the acoustic coupler, a microphone mounted at the end of the first acoustic tube for picking up sound pressure information and a characteristic calculation circuit for transforming an earphone characteristic of the acoustic coupler to an earphone characteristic of a real ear based on an input impedance of the acoustic coupler viewed from an end of the earphone inserted in the acoustic coupler and an input impedance of the real ear represented by a sum of an eardrum impedance of the real ear and an external auditory canal volume of the real ear, stored in a memory in response to the sound pressure information from the microphone

Abstract: A test method for measuring the differential processing time of each side of a subject's auditory system and indicating brain dominance employing an audiometric screening system including signal generation electronics, operator controls, displays and a set of earphones. The system electronics generate left channel and right channel signals to produce complex aural stimuli. The system allows the testor to adjust and monitor the phase of the two aural stimuli, one injected into each ear of the test subject, until subject perceives the source of the sound. The system provides a digital readout of the signal phase, yielding a quantitative measure of the differential processing time of a subject's auditory system and brain side dominance.

Abstract: A hearing aid including a microphone for generating an electrical output from sounds external to a user of the hearing aid, an electrically driven receiver for emitting sound into the ear of the user of the hearing aid, and circuitry for driving the receiver. The circuitry drives the receiver in a self-generating mode activated by a first set of signals supplied externally of the hearing aid to cause the receiver to emit sound having at least one parameter controlled by the first set of externally supplied signals and then drives the receiver in a filtering mode, activated by a second set of signals supplied externally of the hearing aid, with the output of the external microphone filtered according to filter parameters established by the second set of the externally supplied signals. Other forms of the hearing aid, apparatus for supplying the sets of signals to the hearing aid in a total system, and methods of operation are also described.

Abstract: An ear microphone for an external auditory canal insertion type two-way communication earpiece. Within the casing of the earpiece a fixed electrode and a vibrating electrode are positioned in capacitive relation with each other, the vibrating electrode for detecting acceleration vibration from outside the casing in the form of bone-conducted voice sound vibration within the external auditory canal. Electrical signals transduced from picked-up voice sounds pass through an impedance conversion circuit mounted in the ear microphone.

Abstract: An apparatus and a method for performing differential interaural latency evaluation utilizes the ability of the human brain to locate a complex sound source. Respective stimuli are simultaneously applied to the ears of the subject. The stimulus applied to one ear is offset in time with respect to the stimulus applied to the other ear. The stimuli are perceived by the subject as being generated by a sound source inside of the subject's head at a location within the head in accordance with the interaural differential latency. The relative time offset between the stimuli can be varied until the apparent source of the stimuli is perceived by the subject as being in the vicinity of a predetermined position. The time offset is ascertained and used to generate indicia of interaural differential latency, which is displayed by an electronic display.

Abstract: A computerized audiometer is provided with at least one head set, a control switch, a tone generator for providing a plurality of sequential tones of different frequencies and amplifications to at least one head set, and a central processing unit for receiving data representative of the response to the test of the person being tested as reflected by the operation of the control switch. The central processing unit is adapted to analyze the test data and produce a program representative of the correction required by the person being tested. The audiometer is provided with a programming output adapted for coupling to a hearing aid for programming a hearing aid by applying the program developed by the central processing unit to the hearing aid.

Abstract: An audiometer which can be battery operated, is reliable and economical in current consumption has a digital control unit (10) which controls a LCD in matric form (11, 26). The digital control unit, in its simplest form, includes a data input stage (12) having two inputs (16, 18) receiving, respectively, input signals representative of amplitude and tone, or a spoken word, and a further input (14) which is test-person controlled, to provide a perception signal, operated by the person to be tested when the level of a certain tone, generated by a tone generator (G, 21) is perceived, or a spoken word is correctly heard. The data input stage is connected to a data bus which provides the respective data to a driver circuit (24) to drive the LCD matrix.

Abstract: The present invention provides a method and apparatus for diagnosis of various ear pathologies, including the diagnosis of effusions of the middle ear associated with Otitis Media. The method is practiced by determining a quantity related to the complex acoustic impedance of the ear, namely the Vector Sum of an incident signal, propagating down the ear canal, and the same signal reflected from the tympanic membrane and middle ear components. The results obtained are compared with the expected results of a healthy ear.

Abstract: To provide both for soft-switching, that is, elimination of switching clicks, and rapid rise and decay of tone supply from a frequency generator (10) to an audio transducer (13), two electronic switches (11, 16) are provided, one interrupting connection from the source to an audio amplifier amplifying the signals for the transducer, and the other (16) effectively short-circuiting the amplifier, the switches having current transfer/time characteristics to provide for gradual current rise and current decay through the amplifier, and hence gradual rise and drop of the level of output from the transducer with sufficiently steep flanks, however, to effectively eliminate harmonics and hence high-frequency switching clicks. Typical switches use opto couplers with an instantaneous ON optical element such as a light emitting diode (30, 36) illuminating a photo resistor (31, 37) which has resistance change vs. time characteristics following an exponential function.

Abstract: Improvements are described for apparatus used in the measurement of acoustic admittance in ear canals including circuit means for permitting the measurement of relatively small acoustic volumes with an accuracy of better than one percent.

Abstract: Low volume flow measurement apparatus developed for hearing dysfunction diagnosis but also suited to other applications comprises means (10) defining a cavity operably communicable with the variable volume, a D.C. microphone (15) responsive to ambient pressure changes in the cavity due to variations in said volume, and a reference diaphragm (17) operably connected with the cavity and moveable under servo-control responsive to the microphone to maintain the cavity pressure constant. The cavity will normally have a vent valve (18) and in non-hearing application may be coupled with the subject volume by a plunger seal. For hearing diagnosis the apparatus is suitably carried by a helmet (21) or harness with a headphone on the opposite side for sound stimulus application, the helmet itself being at one end of a boom (22) with a counterweight (23).

Abstract: In an exemplary embodiment, for testing the chronological resolution of hearing, acoustic signals are supplied to the ear to be tested via an earpiece and consist of a test tone which can be interrupted and of a masking sound which can be modulated, their frequency and amplitude level being adjustable. Complicated measures are necessary for the measurement of the so-called listening threshold period pattern in order to present a complete pattern for identifying the chronological resolution of the hearing. In contrast, the disclosure provides an uncomplicated measuring device which is also easy to operate and with which the maximum and the minimum of the listening threshold period pattern or, respectively, their difference can be determined. To this end, the disclosure provides a device with channels generating respective sound signals, each of the channels having its own generator.

Abstract: A hearing faculty test and apparatus therefor is based on the findng that sound input to the ear gives rise to a returned wave from and related to the condition of the inner ear, this wave being detectable as an echo from the ear drum. The apparatus preferably comprises a sealing aural probe (1) housing transducers (2,3) respectively to project a repetitive transient sound by pulse generator (4) activation and to pick-up for detection (5) successive echoes by time-gating. Detected echoes are preferably averaged during processing (6) for display. The echo occurs about 5-20 ms after its sound and a maximum operating frequency of about 50 Hz is appropriate. A continuous sound input can be used with consequent echo interference detectable as rapid changes of acoustic impedance with sound input frequency. Another alternative can involve detection of the ear drum movement by returned waves.

Abstract: Apparatus for conditioning the hearing of a patient is disclosed. A signal level detector establishes whether an incoming audio signal is above or below a threshold level to gate the audio signal to one or other of two parallel channels. The first channel has a frequency response curve in which high frequencies are suppressed and thus is the channel used when the audio signal is below the threshold. The other channel has a frequency response curve in which low frequencies are suppressed and this is the channel used when the audio signal exceeds the threshold. Two parallel output stages are provided, one including an electromechanical vibrator which is placed on the patient's skull and the other including earphones worn by the patient.

Abstract: In order to determine the acoustic impedance of a human ear at various static pressures, a probe tightly fitted to the pinna of the ear transmits a short acoustic pulse with a wide frequency spectrum (such as white noise) from an electroacoustic transducer to the ear canal and receives back an acoustic response signal which a microphone converts into an electrical wave. The latter is digitized and transformed into terms of a Fourier series fed to a processor which, on the basis of similar terms stored in a memory and previously obtained with the same probe fitted to two different cylindrical calibrating cavities, derives therefrom the acoustic ear impedance at a particular air pressure. The processor also triggers an electric pulse generator, working into the electroacoustic transducer, and may progressively adjust a generator of static air pressure connected to the probe.

Abstract: A closed sound delivery system includes a sound generating unit coupled to provide sound to an ear in response to electrical input signals and an electrically equalized sound receiving unit coupled to accurately receive acoustical signals provided by the sound generating unit in the vicinity of an ear. The delivery system provides a pressure at the eardrum with a frequency response which remains flat up to about 30 KHz. The sound generating unit includes a low acoustical output impedance transducer and a suppressor element which attenuates acoustical energy emanating from all but a small central region of the transducer to minimize frequency response variations resulting from constructive and destructive interference of acoustical energy originating at different physical positions. The receiving unit has a 6 dB per octave high frequency roll off due to the characteristics of its terminating elements while an electrical high pass filter compensates for this roll off.

Abstract: An electro-acoustic impedance bridge for measuring the acoustic impedance of the human ear over a predetermined frequency range compares the magnitude and phase of the variable-frequency sound driving both the human ear and the artificial ear (acoustic coupler).

Abstract: A hand held ear test probe is disclosed for use in clinical evaluations of hearing problems. There are a number of important tests for evaluating hearing system losses which are based upon measurements taken in patients' external ear canals using a test probe. A probe is described for such tests which is inserted in the patient's ear and which is hand held by the clinician without the use of head bands or other probe supports. The hand held probe has a shaped outer casing which supports the probe and the related ear sealing and pressurizing means as well as the transducers for the transmitted and received audio test signals.