Dedicated Test Chamber TBS25 is a dedicated test chamber with exceptional performance and signal reproduction. It offers a compact solution in situations where maximum attenuation is critical and space considerations are relevant. It can be used with the Equinox and Affinity platforms for hearing aid testing and with a variety of proprietary and non standard equipment.
The future - complex signals The TBS25 is also an investment for the future. Future testing of hearing aids is expected to involve more complex stimuli and demand a higher acoustic performance from the test chamber than needed for pure tones.
Easy to use The compact size and table-top design make it easy to place and use. Internal cable routing eliminates the need for awkward external cables between coupler and reference microphones and the analyzer.
Directional microphones The TBS25 approximates free field conditions above 500Hz and has the speaker in the same vertical plane as the hearing aid. This facilitates testing of directional microphones.
Depending on placement and acoustic surroundings.
Above 300 Hz: 45dB-55dB
100dB SPL at any frequency between 100Hz and 8kHz the typical distortion is:
2nd: < 0,05%,
3rd: < 0,3%
Lower distortion at lower intensities.
TDH at 70dB SPL: Too low to be measured by traditional techniques.
1watt: 110dB SPL at test point.
Max input: 4.5 watts continuous.
40 watts short term.
Nominal 8 ohm. (Max. 25 ohm).
Via high quality loudspeaker
Accuracy of hearing aid response curves
Determined by quality of reference microphone
These specifications indicate typical performance, prior to any applied electronic correction.
50Hz - 8kHz ± 1.5dB.
-3dB points at 35Hz and 10kHz.
6dB/octave cut off below 35Hz.
24dB/octave cut off above 10kHz.
Neither slope suffers from disturbing resonance.
Uniformity of sound field
In measuring area typically +1dB 20Hz-10kHz.
Available levels determined by specifications of connected equipment.
Upper limit: Above 110dB SPL continuous.
Lower limit: Determined by ambient noise level.
50dB SPL test level at 75dB ambient noise changes measurement less than 0.5dB.
35dB SPL test level at 70dB ambient noise has a signal to noise ratio exceeding 10dB.
Approximates to Free Field conditions above 500 Hz. Horizontal sound radiation.
External / internal connections
Reference microphone, coupler, battery adapter, loop, 2 x auxiliary, speaker, additional cables through sound proof passage
40x36.5x26 cm/15.7x14.4x10.2 inch
Net weight: 22 kg/48.5 lbs.
3 TCC25 connection cables
1 TCL25 loop connection cable
1 TSC25 loudspeaker cable
Cable kit for TBS25/Affinity2.0 or Equinox2.0