GB2230158A

GB2230158A - Balanced-hearing hearing aids

Info

Publication number: GB2230158A
Application number: GB8902112A
Authority: GB
Inventors: James Robert Joseph Rutherford
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-02-01
Filing date: 1989-02-01
Publication date: 1990-10-10
Also published as: GB8902112D0

Abstract

A hearing aid in which the microphone 7 the microphone amplifier 6, the band-pass filters 5 with their respective amplifiers 3 and automatic gain controls 4 and the master power amplifier 2 are in a common housing (not shown). The receiver 1 may be in this common housing or may be in a separate earpiece, in which case it is electrically connected to the output of the master power amplifier 2 (Figure 1) by leads. The housing has a shielded opening for the input of sound to the microphone 7 (Figure 1), an opening for the user controlled master power amplifier volume control, and an opening for the insertion or removal of the battery/power source. Another opening is provided for the receiver or leads to the receiver. The housing can be constructed to be ear mounted or worn in the ear or on the body. <IMAGE>

Description

BALANCED-HEARING HEARING AIDS This invention relates to hearing aids.

The main hearing impairment experienced by the hard of hearing is sensorineural and the requirement is to give frequencies with the larger hearing loss equal or higher amplication than those frequencies with the least hearing loss.

The object of this invention is to provide equal or greater amplification between the frequencies of lower or higher hearing loss by means of one or more band-pass filters and their respective amplifiers which are pre-set by use of their respective automatic gain controls so that in use the resultant signal response via a user controlled master amplifier compensates to the need of the user before final amplification by the user controlled master amplifier.

According to the invention there is provided a hearing aid comprising a microphone connected to an amplifier to drive the band-pass filters which are automatic gain controlled via their respective amplifiers, the resultant signal which is applied to the input of a master power amplifier.

The output signal of the master power amplifier is controlled by means of an amplifier volume control before being applied to the receiver.

In order to contain the system physically microcircuitry is used where practical.

In a preferred embodiment the microphone amplifier, the band-pass filters and their respective amplifers and automatic gain controls, and the power amplifier are contained as an integrated circuit in microchip form. A common housing may be provided for the microphone, microphone amplifier, band-pass filters and their respective amplifiers and automatic gain controls, and the power amplifier. Also access space for the battery/power source. The receiver may be in the housing, or outside but in either case is connected to the master power amplifier. Openings may be provided in the housing for the sound input to the microphone, for the master power amplifier volume control, for insertion or removal of the power source, and either for the sound output from the receiver or for electrical leads mounted in a separate earpiece.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows an embodiment of the hearing aid in accordance with the invention, and Figure 2 shows an audiogram of a person with a determined hearing loss.

Referring to Figure 1, there is shown a hearing aid comprising a microphone 7, the output signal of which is applied to a microphone amplifier 6, the output signal of which is applied to the band-pass filters 5, the output signals of which are applied to the band-pass filter amplifiers 3 governed by their respective automatic gain control 4, the output signals of which are applied to the master power amplifier 2 which is user controlled, the output signal of which is applied to the receiver 1. The microphone amplifier 6, band-pass filter 5, automatic gain controls 4, the band-pass filter amplifiers 3, the master power amplifier 2, are contained in a single microchip.

The automatic gain controls 4 bring all the output signals of the band-pass filters 5 and their respective amplifiers 3, to a common level (for example: a pre-determined hearing loss level of 30 decibels). The user may subsequently adjust the volume of this pre-determined hearing loss level by use of the volume control of the power amplifier 2 to a comfortable hearing level so that the volume of sound from the receiver 1 does not reach the level at which discomfort is felt.

As shown in Figure 2 is an audio frequency band of a to e. An audiogram of a person with normal hearing is represented by graph 1 in Figure 2.

An audiogram of a person with a determined hearing loss is represented by graph 3 - 4 in Figure 2, reference 4 representing the minimum hearing loss.

Graph 2 in Figure 2 represents the hearing loss level to which the automatic gain controls and the band-pass filter amplifers are pre-set to equalise the volume of the frequencies with the higher and lower hearing level loss thus making graph 3 - 4 in Figure 2 become graph 2 in Figure 2. Any hearing loss which is less in value than the gain of the band-pass filter amplifiers 3 (Figure 1) and their covering automatic gain controls 4 (Figure 1) is automatically increased to this pre-set level of hearing loss. Thus the determined hearing loss audiogram 3 - 4 in Figure 2 is brought to the hearing loss represented by Graph 2 in Figure 2 before final user amplification using the volume control of the master power amplifier 2 (Figure 1).

Graph 5 in Figure 2 represents the maximum hearing loss.

Claims

1A hearing aid comprising a microphone, connected to a microphone amplifier, connected to one or more band-pass filters with their respective amplifiers and automatic gain controls, connected to a master power amplifier which is volume controlled by the user before the resultant signal is applied to the receiver.

2 A hearing aid as in Claim 1 in which micro-circuitry is used.

3 A hearing aid as in Claims 1 and 2 wherein the microphone amplifier, the band-pass filters with their respective amplifiers and automatic gain controls, together with the master power amplifier are contained in a single microchip.

4 A hearing aid in which the microphone, the microphone amplifier, the band-pass filters with their respective amplifiers and automatic gain controls, together with the master power amplifier are in a common housing.

5 A hearing aid as claimed in any one of the previous claims in which the microphone, microphone amplifier, the band-pass filters with their respective amplifiers and automatic gain controls, together with the master power amplifier are in a common housing which also contains a battery/power source space, and openings are provided in the housing for sound input to the microphone, for the master amplifier volume control, for insertion and removal of the power source, and for the output of the receiver, or for leads to a receiver mounted in an earpiece.

6 A hearing aid substantially as hereinbefore described with preference to the accompanying drawing.

Amendments to the claims have been filed as follows 1A hearing aid comprising a microphone, connected to a microphone amplifier, connected to two or more band-pass filters with their respective amplifiers and automatic gain controls, connected to a master power amplifier which is volume controlled by the user before the resultant signal is applied to the receiver.

2 A hearing aid as in Claim 1 in which micro-circuitry is used.