search for: 300hz

Does asterisk have a way in the dialplan to generate tones? Say I want to play a tone 300Hz for 3 seconds. Can I do that? If not, can I use some system command to generate the wav file then just have asterisk play it? Jerry

Hi, But in fact, it really affects the voice quality. One of my tester says, "Is your mouth far way from the mic?" Could you explain why we should cut 200hz below? >The notch filter is specifically designed to cut below 200 Hz when >working in narrowband. In wideband, the cutoff is more around 50 Hz. The >reason is that in narrowband operation (irrespective of the

...y. Low bit rate codecs, like G.729 or speex, usually apply their own fast rolloff filter for low frequencies - e.g. G.729 rolls off its input hard, with a turnover at 140Hz - their whole coding methodology tends to break down without that. The telephone network normally rolls off hard below about 300Hz, so this actually perfectly normal voice for a phone call. A second reason to remove the bass frequencies is if you don't you can get nasty echoes if the audio is sent to the PSTN. Analogue PSTN interfaces don't always remove the bass frequencies, and digital interfaces (BRI/E1/T1) never d...

...ectrum (int32[] of squared values) */ +#define SPEEX_PREPROCESS_GET_POWER_SPECTRUM 39 + +/* Can't set noise estimate */ +/** Get noise estimate (int32[] of squared values) */ +#define SPEEX_PREPROCESS_GET_NOISE_ESTIMATE 41 + +/* Can't set SNR */ +/** Get signal to noise ratio estimate for 300hz-2000hz range (int32 (scaled by 100)) */ +#define SPEEX_PREPROCESS_GET_SNR 43 + #ifdef __cplusplus } #endif Index: include/speex/speex_echo.h =================================================================== --- include/speex/speex_echo.h (revision 14443) +++ include/speex/speex_echo.h (working...

Ok here is a real geek question, I building my own linux kernel for my asterisk system and came across the kernel setting for the timer frequency. I have one of 3 hardcode choices 100Hz, 250 Hz and 1000Hz. From what I understand the default Freq was changed from 100Hz in kernel 2.4 to 1000Hz (1KHz) in kernel 2.6. Timing is a BIG issue in asterisk with all the TDM and zap channel stuff.