GB2107502A - Auditory teaching laboratory apparatus - Google Patents

Abstract

An auditory training system for individuals with severe hearing difficulties utilizes a limited range radio system for communications from an instructor having a transmitter 20 to one or more students having receivers 30. A visual telemetering indication of the status of the students' receivers is provided to enable the instructor to maintain constant awareness of the integrity of the radio system so as to know whether or not individuals participating are capable of receiving communications from the instructor. An LED indicator 34, responsive to an RF carrier signal emitted by transmitter 20, is provided on each receiver 30 so that the instructor is visually aware that the student is receiving an instruction. A low battery indicator 19 may also be provided. <IMAGE>

Description

SPECIFICATION Auditory teaching laboratory apparatus 1. Field of the invention This invention relates to auditory teaching laboratory apparatus and is more particularly directed to teaching laboratories of the class wherein both the instructor and the students are ambulatory and in which a variety of learning situations are disposed within a teaching laboratory environment. In one type of system, students, having substantial hearing losses, may receive communication through portable radio receivers that are typically battery operated. The instructor is similarly equipped with a battery operated transmitter.In the environment of this class of teaching laboratory, the instructor needs to be aware of the integrity of the communications system because the instructor cannot always tell from the reactions of the students to learning instruction whether or not the instruction has been received.

2. Prior art In a typical auditory teaching laboratory environment of the prior art of which applicant is aware, an instructor is provided with a wireless microphone that transmits to a transponder that retransmits the instructional materials to wireless student receivers, that may also function as hearing aids. The instructor had no way of knowing the operational status of the student instruments and therefore has been unable to fully interpret the reaction of the students to a given set of instructions.

BRIEF SUMMARY OF THE INVENTION In the teaching laboratory apparatus of my invention, telemetering means is provided to inform the istructor of the integrity of the system with respect to the status or ability of the student to receive communications. In one embodiment of my invention, a visual telemetering means is utilized to provide the instructor with an indication of the operational integrity of a radio frequency communications system and/or the operational status of a battery supply for portable, body worn students' receiving instruments. Other forms of telemetering means may also be implemented to alert the instructor to various malfunctions that may occur in a communications system as well as to supervise the Integrity of the operational status at any given time in the program.

In one such system, an indicator light is provided on a portable student receiver to provide a visual indication of the operational status of the radio frequency receiver elements of the student instrument by sensing the continued reception of the relevant radio signal emanating from the instructor's transmitter and responding to such a condition to extinguish a malfunction indicating LED indicator.

These and other objects of my invention will become apparent from a consideration of the appended specification, drawing and claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top plan view of an auditory teaching laboratory enviroment; Figure 2 is a fragmentary front view of an instructor for the laboratory; Figure 3 is a fragmentary front view of a student in the laboratory; and Figure 4 is a block diagrammatic and schematic drawing of a communications system for use in the laboratory, DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring to Figs. 1,2 and 3, an instructor is indicated generally by reference character 21 and a student is indicated generally by reference character 31. A frequency modulated transmitter 21 having an antenna 22 is shown supported around the neck of instructor 21 by a lavaliere or the like. Similarly, a body worn combination frequency modulated radio receiver and hearing aid apparatus, indicated generally by reference character 30, is shown disposed on a student 31.Receiver 30 is shown including a receiver in the form of an ear piece 32 connected through a cable 33 to student receiver 30, a no FM LED indicator 34, a low battery indicator 1 9 and an antenna 35 typically within cable 33. Student receiver 30 may be supported on the body of a student by suitable means such as a harness, belt clip, lavaliere or the like.

It may be appreciated that in the laboratory environment illustrated in Fig. 1, the instructor, as well as a plurality of students, are typically ambulatory and may engage in any one of a number of learning activities at various and sundry locations throughout the area. To an extent, determined by the hearing malfunctions of individual students, the student receivers 30 may be operated as high power hearing aid instruments or, as is typical, part of a freqency modulated communications system.A frequency modulated system that has been utilized in operational systems embodying the principles of my invention is operational in the spectrum of frequencies assigned by the Federal Communications Commission of the United States government in the 72-76 MHz band and the transmitter includes a suitable microphone (not shown) and an antenna 22 for radiating the frequency modulated signal into the enviroment of the laboratory.

The student receivers 30 include appropriate frequency modulation processing circuitry for converting the received signals to an audio signal that is subsequently applied to the auditory sense organs of the students through, typically, a receiver 32. Receiver 32 may also be energized from an internally disposed (not shown) high powered hearing aid, a recorded source af audio program material or any other learning program media. Both the transmitter and receivers are typically battery operated.

Referring to Fig. 4, an instructor's transmitter 20 and its antenna 22 are illustrated in the lower left hand corner of the drawing and students' receiver 30 is contained within the dotted outline of the remainder of the drawing.

Receiver 30 includes a receiver front end 36, connected to antenna 35, and contains suitable circuitry and apparatus for converting any received frequency modulated signals to a lower intermediate frequency, typically known as a first intermediate frequency, that will be further processed as set forth below. Front end 36 may be energized from a suitable source of power (not shown) in the form of a battery or the like.

A low power intermediate frequency integrated circuit chip is shown in dotted outline as indicated by reference character 37.

Integrated circuit 37 includes an output terminal 9, a filter input terminal 1 0, a filter output terminal 11, a trigger input terminal 12, a muting input terminal 14, a ground terminal 1 5 and an input terminal 16, connected to the output of a receiver front end 36 through conductor 1 8.

Integrated circuit 37 also includes an active filter amplifier 38 connected intermediate terminals 10 and 11 and a trigger amplifier 39 connected intermediate terminal 1 2 and terminal 41 on switch 40.

Output terminal 9 on integrated circuit 37 is connected to a receiver 32 through conductor 45, terminal 46, resistor 47, conductor 48, terminal 49, receiver audia amplifier 44 and conductor 33. Terminal 49 is connected to ground through capacitor 50. Terminal 9 on integrated circuit 37 is also connected to filter input terminal 10 through conductor 45, terminal 46, capacitor 51, resistor 52, terminal 53, capacitor 54 and terminal 55. Resistor 56 is shown connected intermediate filter terminals 10 and .11 on integrated circuit 37 through terminal 57 and conductor 62. A capacitor 61 is connected intermediate terminals 53 and 57 through conductor 58 and terminal 59 and terminal 59 is connected to ground through resistor 60.

Filter output terminal 11 on integrated circuit 37 is connected to trigger terminal 1 2 through conductor 62, terminal 57, conductor 63, terminal 64, diode 77, terminal 66 and conductor 65. Diode 77 is connected in series with diode 76 and to ground through terminals 72 and 75 and capacitor 74, having resistor 73 connected in parallel therewith; capacitor 69 and resistor 68 are shown connected in parallel across diodes 77 and 76 and terminal 75 is shown connected to a source of positive potential, at terminal 84, through terminal 72, terminal 71, conductor 70, resistor 81 and terminal 83. Muting switch terminal 14 on integrated circuit 37 is shown connected to terminal 49 through conductor 80, terminal 79 and conductor 78.

Muting terminal 14 on integrated circuit 37 is connected to stationary contact 42 on switch 40 and ground terminal 1 5 on integrated circuit 37 is connected to moveable contact 43 on switch 40.

At the upper right hand portion of Fig. 4, a pair of transistors 88 and 95 are connected to control the energization of a light emitting diode 34. Transistor 88 is shown having its base electrode 89 connected to terminal 83 through resistor 87, terminal 86 and resistor 85; collector electode 91 on transistor 88 is connected to positive terminal 84 through resistor 93: and emitter electrode 90 is shown connected to ground. Base electrode 96 on transistor 95 is connected to collector electrode 91 on transistor 88 through conductor 94 and terminal 92; collector electrode 98 on transistor 95 is connected to a source of positive potential at terminal 101 through resistor 100 and LED 34; and emitter electrode 97 is connected to ground through conductor 99. Terminal 86 intermediate resistors 85 and 87 is shown connected to terminal 14 on integrated circuit 37 through terminal 79 and conductor 80.

The following is a table of values for the reievant components for the illustrative embodiment of Fig. 4; Reference Character Component 1 9 Integrated circuit type cherry semi-conductor CS 1 88 and LED type Litronix LD36C 34 LED Litronix LD 32-2 37 Integrated circuit- Motorola P/N type MC 3357 47 10K ohm resistor 50 .001uf capacitor 51 .0047 uf capacitor 52 5.6K ohm resistor 54 120pf capacitor 56 180K ohm resistor 60 2.7K ohm resistor 61 120pf capacitor 68 100K ohm resistor 69 1 Ouf capacitor 73 22K ohm resistor 74 1.0us capacitor 76 type IN4148 diode 77 type IN4148 diode 81 39K ohm resistor 85 100K ohm resistor 87 100K ohm resistor 88 and 95 type SGS L159M3 transistor array 93 56K ohm resistor 100 820 ohm resistor OPERATION OF THE ILLUSTRATED EMBODIMENT It may be assumed that one or more instructors and a plurality of students are present in a laboratory environment as in Fig. 1 of the drawings and that the instructors are in possession and control of a transmitter 20 and that each of the students is similarly in possession and control of a student's receiver 30. The instruments are provided to be in readiness with the transmitting and receving elements energized from the batteries in each of the units. A visual telemetering signal to indicate a low battery may exist on one or more of the instruments and the instructor is able to discern this malfunction and correct the same before proceeding with a teaching program.Again, assuming that all of the portable units are in an operational status, the instructor proceeds to communicate with the students through the frequency modulated system.

If each of the student receivers is receiving a transmitted signal, the visual telemetering indicator light 34 which may preferably be red in color on each of the student receivers is not illuminated and the instructor may then proceed with communication to the students with the assurance that the messages and instructions are being received by each of the students.

Briefly, when transmitter 20 is suitably energized, a carrier wave of a predetermined frequency is transmitted throughout the laboratory enviroment and to each of the student receivers 30. The frequency of the carrier wave is converted to a first intermediate frequency in receiver front end 36 and is supplied to input terminal 1 6 on second intermediate frequency integrated circuit 37 through conductor 1 8. The typical second conversion and detection is carried out by portions of integrated circuit 37 that are not indicated on the drawing but which supply an output, that may contain modulation and other signal components, at terminal 9 that is in turn supplied to amplifier 44 and to receiver or ear piece 32 disposed to stimulate the auditory sense organs of a student.The output appearing at terminal 9 is also connected to terminal 1 2 on integrated circuit 37 through filter amplifier 38 and an AC-DC converter. Filter amplifier 38 and the components connecting terminal 9 to terminal 10 comprises a band pass filter having a nominal frequency of 80khz. It may also be noted that the AC-DC converter is operative to reduce the voltage appearing at terminal 1 2 as the signal output from band pass filter amplifier 38 increases. Under normal communication with the system, trigger 39 is operative to control switch 40 in the position shown in Fig. 4.

In the event the output at terminal 9 on integrated circuit 37 contains a substantial frequency component of 80khz, such as is normally encountered in the absence of a carrier wave signal at the transmission frequency of the FM system, or from other interferring causes, the output at terminal 11 on integrated circuit 37 will increase and the AC-DC converter will cause a reduction in the potential appearing at terminal 1 2 to actuate trigger 39 which in turn will cause switch 40 to actuate its moveable contact 43 into engagement with stationary contact 42 to ground the signal appearing at terminal 9 as well as to energize LED 34 by rendering transistor 88 non-conductive and rendering transistor 95 conductive.

The illumination of LED 34 will alert the instructor to the existence of a malfunction in the system that must be corrected before communication with the student using that particular receiver may be resumed. While the mode of telemetering a system malfunction of the illustrated preferred embodiment utilizes a visual medium of communication, it may now occur to those skilled in the art that other forms of telemetering devices may be utilized to alert the instructor to the existence of the malfunctions discussed above in connection with the illustrated embodiment and others that may arise.

Similarly, the low battery indicator on student receivers 30 is intended to be representative of a further means for telemetering information concerning the student's receivers 30 to the instructor so as to ensure the integrity of the communications of an instructional program.

Claims (4)

1. In a wireless auditory teaching system, the combination comprising; a portable instructor's transmitter including means for emitting a radio frequency carrier signal within a teaching enviroment; at least one portable student's receiver to be operated in said teaching environment, said receiver including telemetering means for emitting at least one signal representative of the operable status of said receiver whereby an instructor may be aware of a student's ability to receive instruction communications.

2. The apparatus of claim 1 in which the telemetering means is operable in a visual medium.

3. The apparatus of claim 2 in which the telemetering means is operable in response to the presence of a radio frequency carrier signal.

4. The apparatus of claim 3 in which the student's receiver includes means for actuating the telemetering means whenever the radio frequency carrier signal is less than a predetermined level.