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Hw do we supress 50/60hz hum in the codec if the codec doesnt have any high pass filte
option?

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d...@gmail.com wrote:

> Hw do we supress 50/60hz hum in the codec if the codec doesnt have any high pass filte
option?

The simplest thing would be to high-pass the speech before you send it 
to the codec. However...

Unless the hum is of very high amplitude compared to the speech it will 
be automatically removed by most speech codecs. Think about it, most 
codec encoders determine the fundamental frequency, or pitch, of each 
speech frame, so the hum will likely be ignored. And at the decoder end 
it will not be reproduced.

-- 
Phil Frisbie, Jr.
Hawk Software
http://www.hawksoft.com

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Hi Dinesh,
   
      Use notch filter with cut of frequency centered around 50hz. Practical purpose use second
order Notch filter. Notch filters are suitable for the removing particular frequency.
   
  With regards
  Amaresh
   
d...@gmail.com wrote:
          Hw do we supress 50/60hz hum in the codec if the codec doesnt have any high pass
filte option?

(You need to be a member of speechcoding -- send a blank email to speechcoding-subscribe@yahoogroups.com )

Hi All,
  If any one have good document/pdf about Notch Filter, please forward it to me.
   
  Regards,
  Nihal

Amaresh patil <a...@yahoo.com> wrote:
          Hi Dinesh,

Use notch filter with cut of frequency centered around 50hz. Practical purpose use second order
Notch filter. Notch filters are suitable for the removing particular frequency.

With regards
Amaresh

d...@gmail.com wrote:
Hw do we supress 50/60hz hum in the codec if the codec doesnt have any high pass filte option?

(You need to be a member of speechcoding -- send a blank email to speechcoding-subscribe@yahoogroups.com )

hi,
You can start by doing some experiments using Matlab. There is no
specific documentation about notch filters. You cand synthesize it
using FDATool under matlab.
Cheers
--- In s...@yahoogroups.com, Nihal Ahmad <q_nihal@...> wrote:
>
> Hi All,
>   If any one have good document/pdf about Notch Filter, please
forward it to me.
>    
>   Regards,
>   Nihal
> 
> Amaresh patil <amaresh_p@...> wrote:
>           Hi Dinesh,
> 
> Use notch filter with cut of frequency centered around 50hz.
Practical purpose use second order Notch filter. Notch filters are
suitable for the removing particular frequency.
> 
> With regards
> Amaresh
> 
> danesh.8@... wrote:
> Hw do we supress 50/60hz hum in the codec if the codec doesnt have
any high pass filte option?
>

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