Patent ID: 6154546
Filing Date: 2000-11-28
Classification: H04R

Abstract:
A method for making real ear measurements during a patient fitting of a digital hearing aid (DHA), the DHA having a direct audio input and at least one DHA microphone, the method comprising the steps of:converting sound signals into a first electrical signal using a first DHA microphone;directing sound signals from a region inside the patient's ear to a first probe microphone disposed exteriorly of the DHA;converting the directed sound signals into a corresponding second electrical signal using the first probe microphone; anddigitizing the first and second electrical signals using the DHA to thereby generate digital representations of the first and second electrical signals,wherein the step of converting the directed sound signals comprises:sensing an output of the first probe microphone using a switchable circuit, the switchable circuit capable of switching between a first mode responsive to a first sound range and a second mode responsive to a second sound range, the first and second sound ranges being substantially different from one another;sensing the output of the first probe microphone in the first mode; andsensing the output of the first probe microphone in the second mode,and wherein the switchable circuit is an attenuator with ON/OFF states, the attenuator comprising a circuit connected to a switching device such that the circuit is connected to any one of the voltage levels comprising ground, virtual ground, or V.sub.DD when the switching device is switched on in the first mode and is disconnected from said voltage level when the switching device is switched off in the second mode, V.sub.DD representing the lower of two power supply levels connected to the attenuator.