PRODUCT SELECTION BOOKLET
Removing unwanted background noise and interference from voice
and radio communication channels to leave clear audible speech
bhi Ltd design and manufacture
a range of DSP noise cancelling
products that remove unwanted
noise and interference from noisy
radio and voice communication
channels. Unwanted background
noise, white noise, hiss, hash,
plasma TV interference, computer
hash etc can be removed so that
you can hear the speech signal
much more clearly, enabling you
to listen stress free!
2
Proudly serving the following markets:
MilitaryCommercial MedicalAmateur
bhi DSP noise cancelling technology operates in the frequency domain and the
software algorithm recognises human speech. The system works out whether the
received signal has speech or noise characteristics. The typical range of human
voice modulation is around 0.6 to 6Hz.
The pass-band of the bhi DSP technology is subdivided into sub-bands, and if the
signal has noise characteristics, the noise portion is removed from this sub-band.
The speech then passes through with the noise removed (depending on the lter level
setting). If no noise is present the speech remains unchanged (try it with a clear FM
signal). A technique called “spectral diffusion” is used to minimise the phenomenon of
“musical tones” that you can nd with other DSP technologies for most lter settings.
How does bhi DSP Noise Cancelling Technology work?
3
There is almost no distortion of the speech signal, even for very low signal-to-noise
ratios of 0 dB. The bhi DSP technology is self-adapting to a changing noise
environment, and no training of the noise lter is required.
Customers can adjust the DSP lter level to suit their own needs and application.
When doing this, it does not change the characteristics of the noise, that is, any
residual noise still sounds natural.
0.1
-35
-30
-25
-20
-15
-10
-5
0
1
Typical range for voice modulation
10
Suppression level
Level 8
Level 7
Level 5
Level 3
Level 1
bhi DSP Noise Cancellation Product Selection Chart
4
Do you use an extension speaker or headphones?
If yes, go to [A]
If no, go to [B]
1. NEDSP1061-KBD - Suitable for many amateur radio transceivers and receiver installations,
tted in the receive audio path. Note: This involves the removal of small SMD components and
should only be carried out by someone with the appropriate electronic skills.
2. NEDSP1061-PCB, NEDSP1068-PCBA, NEDSP900 commercial install modules suitable for a
variety of radio and voice communication applications.
[C] - Low level audio DSP noise cancelling modules
Do you listen to stereo signals or use more than one radio simultaneously?
If yes, select Compact In-Line or Dual In-Line
If no, select NEIM1031MKII or ANEM MKII or NEDSP1062-KBD
[A] - In-line units
Would you like to retrot one of our low level audio DSP module inside your radio?
If yes, go to [C]
If no, go to [D]
[B] - Amplied DSP speakers & internal low level audio DSP modules
Do you operate mobile?
If yes, select the NES10-2MK3 or DSPKR
If no, select the DESKTOP, NES10-2MK3 or DSPKR
[D] - Amplied DSP speakers
Use the selection path below to choose your bhi DSP noise cancelling product:
5
Product Description Speaker
Headphone
Socket
Speaker
Socket
Line
Level
Audio
Internal
Install
DSP
Filtering
Audio
Power
(Watts)
DSPKR
DSP Noise Cancelling
Speaker
10
NES10-2-MK3
DSP Noise Cancelling
Speaker
2.5
DESKTOP
DSP Noise Cancelling Base
Station Speaker
10
NEIM1031MKII
Amplied inline DSP Module
3
Dual In-Line
Dual channel DSP noise
eliminating
inline module
7
Compact-In-Line
Dual channel DSP noise
cancelling module (Portable)
0.2
ANEM
Compact inline DSP module
3
NEDSP1061-KBD
Low-level audio DSP module
NEDSP1062-KBD
Amplied DSP Speaker
Module
NEDSP900 / NEDSP1061PCB / NEDSP1068-PCBA
Low level audio DSP
PCB modules
bhi Product Selection Table
Note: All bhi DSP noise cancelling products are designed to minimise the effects of RF interference.
Loading...