Abstract:
A system and method of measuring the linear and nonlinear response of an unknown acoustic termination uses a small probe assembly containing a sound source and microphone to determine the reflection function of the unknown acoustic termination. The probe assembly is used with a calibration tube to calculate an electrical signal that will provide a desired acoustic stimulus signal to the acoustic termination. The calibration tube is also used to characterize the signal processing properties of the sound source and microphone, as well as other associated signal processing circuits such as amplifiers, filters, and the like. The calibrated system is subsequently coupled to the unknown acoustic termination to deliver the acoustic stimulus signal. The reflection function is indicative of the power transferred to the unknown acoustic termination. The measurement of the linear transfer characteristic is applicable to any unknown acoustic termination such as a musical instrument or the auditory system. The probe assembly is sized to be positioned directly within the outer portion of the ear and measure the linear characteristics of the ear. The system is further able to measure the nonlinear transfer characteristics of the ear by measuring the linear response at multiple levels of the acoustic stimulus. The system is particularly useful in testing the response of the middle ear and inner ear of humans or other animals.
Abstract:
An apparatus for testing hearing comprises a sound source (3) for applying a sound to the subject's ear and a sound detector (5) for detecting the sound returned from the subject's inner ear in response to the sound. The sound source (3), which is driven by stimulus generation equipment (2) connected to an analyser (1), produces a sequence of sounds constituting a maximum length sequence (MLS) to record Evoked Otoacoustic Emissions.
Abstract:
A hearing aid fitting system includes a computer having a graphical display which controls apparatus that can program and evaluate an adjustable, multi-band hearing aid. The fitting procedure implemented on this system determines the combined frequency response characteristic of the hearing aid and a client's ear, determines maximum amplification factors which can be implemented in each channel without inducing feedback, and automatically adjusts the hearing aid so that the combination of the client's loss curve, the determined combined frequency response characteristic, and the adjusted hearing aid match a target curve. The target curve and the loss curve may be graphically specified and adjusted using the computer.
Abstract:
A system for testing the auditory response of the human ear by measuring the linear and nonlinear power-based responses thereof uses a small probe assembly (50) containing a sound source (24, 52, 54) and microphone (30, 52, 56) inserted into the ear. The linear responses, or transfer functions, include reflectance, admittance and impedance. A calibration procedure is based upon measured pressure responses in one or more calibration waveguides (60), and upon a model of the transfer function of each of the calibration waveguides. The nonlinear responses are established by measuring the above transfer functions at different levels of the acoustic stimulus. By delivering changes in static pressure applied to the ear via an additional probe tube (68, 70) in the probe assembly (50), the system is able to measure the dependence on static pressure of any of these linear and nonlinear power-based functions.
Abstract:
A hand-held, battery-driven, oto-acoustic emission analyser (1) comprises an apparatus housing with two areas; an elongated housing part (6) for the electronic circuits (13, 14, 16), a measuring probe (2) and a display (5), and a handgrip part (7) comprising a power supply unit (8) in the form of a battery compartment and a pump (9), e.g. a mechanical, hand-operated pump.
Abstract:
A noninvasive procedure for detecting and analyzing joint disorders utilizing an acoustic signal processing technique. The diagnostic procedure graphically correlates joint induced sound patterns (12) relative to the joint position in time and space (10) thereby providing a quantitative approach for the diagnosis of specific joint disorders. The present invention, termed Arthrophonometry, is particularly well suited for differential diagnosis of the temporomandibular (TMJ) joint. A microphone (28) detects the joint sounds and an accelerometer (36) detects the joint positions. An oscilloscope (34) graphically correlates the joint induced sound patterns and joint positions.
Abstract:
An audiometer system for selectively generating audiologic test signals of selectable kind and intensity to be used in audiometric testing of the hearing abilities of persons. A repertoir of test signals and patterns is prestored in a source of test signals (52, 54), each test signal having a corresponding unique address. Control means (60, 66, 68, 70, 74) including a tablet (68) or a display screen unit (70) enable an operator to manually select desired test signals from said prestored repertoir. The operator's selection causes said control means to address said source of test signals (52, 54) so as to reproduce the desired test signals. Said source of test signals may be a digital disc player (52) having a removable disc (54) containing said repertoir prestored thereon as digital signal representations.
Abstract:
A hearing faculty test and apparatus therefore is based on the finding 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 50Hz 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:
A hearing evaluation and hearing aid fitting system (22) provides a fully immersed, three-dimensional acoustic environment to evaluate unaided, simulated aided, and aided hearing function of an individual. Digital filtering of one or more signal sources representing speech or other audio-logically significant stimuli according to selected models and digitally controlled signal processing parameters produce a simulated acoustic condition for presentation to a hearing impaired person for hearing evaluation.