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SLS - Loop systems. univox Loop Systems, since 1965. Conventional loops:. Overspill (energy/space wasted leakage) Head tilt problem (directivity) Acoustic and Inductive feedback/interference Metallic influence/interference Variable field - level / frequency drop in middle area
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SLS - Loop systems univox Loop Systems, since 1965
Conventional loops: • Overspill (energy/space wasted leakage) • Head tilt problem (directivity) • Acoustic and Inductive feedback/interference • Metallic influence/interference • Variable field - level / frequency drop in middle area • Needs experienced expertise for planning
Conventional loops - tilt angel -3dB (@45°) -3dB (@45°) Vertical field 0dB=full level Silence! Silence!
New Loops- both directions -3dB (@45°) -3dB (@45°) Vertical AND Horizontal Field 0dB=full level full level full level
SLS-XF, second generation • One unit, 2 matched stages and built-in SLS-filter • Increased internal high frequency range 10-16 kHz • Fully matched output stages and filter • Super safe technology • 12 Power transistor of each 25A current capability • Increased output voltage: 30Volt – 50Volt • Built-in auto-SCART-function
IEC 60118-4 standard univox Loop Systems, since 1965
IEC 60118-4, Scope + Facts Specifies the Field strength • Background noise less than -47dBA, -32dBA • Frequency range 100-5000Hz • Field variation +-3dB • Level 0dB = 400mA/m (clarity and less noise)
IEC 60118-4, Comments • Loop Amplifier can NOT be IEC 60118-4 approved • IEC 60118-4 Specifies ONLY the Field Strength • Do NOT trust the stated coverage area for Loop Amplifier • Trust the written certificate from the installer • Compare the output current and/or power consumption for Loop Amp • Measurement report - certificate • Level = 400mA/m for speech (clarity, no noise)
High Noise, Low field strength FieldStrength -12dB (16-times less power below standard) Noise -12dB (20 dB higherthan the standard)
Field comply but Noisy Field Strength 0dB=400mA/m Noise -12dB
Minimum IEC-standard! Field Strength 0dB Noise -32dB
Wirelesssystem needed! • Do NOT trust statedcoverage area! • Certifyaccording to IEC • LEVEL = 400mA/m (0dB) • Do NOT certifyusing a Hearing Aid.
Why a Loop System? univox Loop Systems, since 1965
Why a Loop System? Sound in air has problems: • Distortion • Echo • Reverberation • Absorption • Noise> human speech noise • Frequency limitation
Hearing Aid, Mic-input • 2 secreverberation time, largebuilding-church • Speaker 4m • Babblenoise (other speakers) • Direct from a Hearing Aid (artificialear)
Wirelesssystem needed! • Difficult to filter out reverberation • Impossible to filter out speech from speech • Solution: shorter microphone distance (wireless system)
IR – Radio - Loops • IR – infrared • No overspill • Different frequencies – partly standardized • Sensitive to direct sun light • Radio and Infra Red (IR) • High current consumption compared to HA (0.3-1.5mA) • Not Compatibility with Hearing Aid (neck loop) • Separat unit outside HA • No world-wide standard (2.4GHz streamers, not standardized)
Loop System – fundamentals • Built-in reciever in HA • Zero Current consumption, T-coil • World Wide Standard
Loop Systems – usersview • Invisible • Economical = No extra costlyunit • No additionalknowledge • No channelswitching, level setting • No changingbattery/charginghassle • Economical = No extra unit+ZeroCurrent • Long life = system is not tampered with • Individualfitted hearing aid • Compatibleeverywhere-World Wide
Thank you for your attention! Conny.Andersson@edin.se