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Hearing Enhancement Systems

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Hearing Enhancement Systems

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    1. Hearing Enhancement Systems A presentation by John Popplestone Connevans Limited

    2. Hearing Enhancement Systems Audio Frequency Induction Loop Systems Soundfield Systems Personal fm Systems

    4. The problem using a hearing aid Background noise Room acoustics

    5. Why do we use loops or fm Systems?

    6. Audio Frequency Induction Loop Systems Sometime referred to as AFILS more often just called loops. They operate by generating a magnetic field in the area where they are used. When the HA is within the magnetic field an induced current can be picked up by the telecoil in the HA and then amplified by the HA circuit to be produced as sound.

    8. AFILS design considerations Getting the wanted sound into the loop system. It is not much use just putting a microphone in the ceiling and expecting it to be any better than just using the HA on its own. The microphone needs to be close to the sound source.

    9. AFILS design considerations cont

    10. AFILS design considerations cont

    11. AFILS design considerations cont

    12. AFILS design considerations Low overspill designs can allow loops to be run side by side but they are more expensive and the loop array needs to be positioned under the floor covering Even with low overspill loops there still needs to be vertical separation.

    13. What size of amplifier do I need? The power of the amplifier is dependent on the size of the area to be covered. Consideration need to be made of the construction of the building. Metal in the construction can cause losses due to absorption of the magnetic field and may also require frequency response correction.

    14. What other factors do we need to consider? Are there existing magnetic fields that could be picked up on the T setting of the HA. These could, amongst other things, be large electrical supply feeder cables, heavy duty electrical equipment, lift motors, incorrectly wired low voltage lighting systems and electrical under floor heating.

    15. Advantages of Loop Systems A HA with a T setting does not require any other equipment to make use of the Loop System. Reduction in unwanted background noise. Improved signal to noise ratio.

    16. Common applications for AFILS Lecture Theatres Public Performance Venues Village Halls Meeting Rooms Reception Counters Bank and Post Office Counters

    17. Soundfield Systems An amplification system which provides an even spread of sound round the room. It allows all students to hear equally well wherever they are seated.

    18. Soundfield Systems Although their prime use is in the education setting they are also used in other Public Areas such Retirement Homes, Village Halls etc.. Quite often in this type of environment they are also used in conjunction with loop systems but not usually in the classroom.

    19. Soundfield Systems The transmission system between the speaker and the receiver/amplifier can be either Radio or Infra Red. There are specifically designed classroom systems that incorporate the receiver/amplifier in one compact unit. For larger hall systems they are usually made up of separate components mounted in a rack mount cupboard

    20. Soundfield Systems

    25. Personal fm Systems Usually referred to as Radio Aids. They are totally portable and require no installation. The user has control of the system and takes it with them to wherever they need it.

    26. Transmitter is worn by the person who is speaking. The receiver is worn by the listener. It can be used with a neck loop, direct connection to the hearing aids or with headphones.

    27. Basic one to one situation

    28. Teaching situations

    29. In meetings with a conference microphone

    30. Summary Loop, Infra Red and fm Systems are designed to improve the signal to noise ratio, reduce background noise and transmit the wanted sound to the user. Soundfield Systems enhance the listening environment and benefit everyone from those talking to those who are listening.

    31. Thank you for listening.

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