Echo on received audio

[VE7TL]

I have a variable problem with echoes. The audio often sounds OK but on occasion, there seems to be a variable delay varying from an "arctic flutter" sound to approximately 1/10 second echo. This is the same for all filters made for me. When I shift to bypass it becomes worse, almost sounding like a triple echo. CW becomes impossible to read. This is the same on strong or weak signals and regardless of the filter level.

Any ideas what is happening and how to fix?

Paul, VE7TL

[RandyW]

BYPASS routes the audio from the input device straight to the output device without processing, so I'm guessing the problem may be outside of RM Noise.


a) If you stop the stream in RM Noise (OPTIONS ->[uncheck] filter audio at the server) do you hear anything?


b) Do you have microphone input to the computer? (Windows may be set to "listen to this device" under settings->system->sound->more sound settings->recording [tab]->microphone->properties->listen).

c) While you are at it, check all of the devices under the "recording" tab.


d) Another thing I would try is to play the first minute or so of the demo recording:
https://ournetplace.com/rmnoise/rmnoise-demo-1.wav

This will eliminate the input side of the stream. Do you hear an echo with the demo recording?

[VE7TL]

Randy,

The distorted audio was not heard in my IC 7300. No distortion on RM Noise for the first 10 minutes today but then it occurred. When I stopped the stream, the echo stopped. Maybe a problem with the incoming processed audio? Input from receiver is via USB. No problem with the demo recording.
I doubt it is my PC settings because the flutter occurs by itself with no change in settings. Sometimes it goes away with no change

Paul, VE7TL

[RandyW]

Paul,

When you are experiencing the echo, record several minutes of that audio. Afterwards, notify me and I will examine it.

[VE7TL]

Randy,

With bad CME today, not many signals on the band. I did record WWV on 15 MHz. I could hear the echo through your program but the recording did not show it. I also recorded a video of a Broadcast band (local) which had heavy echos but was unable to attach it. Some problem with format. I also submitted some Broadcast band recordings but they did not show up in the rejected recordings file. How can I submit a sound recording as heard here?

Paul, VE7TL

[VE7TL]

Randy,
I have a Video and audio recording which I can send to you. How to attach? MOV is an invalid file.

[RandyW]

How can I submit a sound recording as heard here?

The easiest might be cloud storage. You can send the link to rmnoise@ournetplace.com.

I agree that the recording did not have an echo. I also took a look at your logs, but didn't see "out of order" packets, and a reasonable amount of packet loss.

I'm quickly running out of suggestions. These observations seem to cover the audio's entire round trip:
a) An echo during bypass eliminates the server and network
b) When a recording of the input was good, it suggests the input from the soundcard works
c) Playing a recording without issue suggests that output to the soundcard works


You mentioned that sometimes it works for a number of minutes. You could record 30 minutes of ragchew, then play it back. Maybe the problem will manifest itself either in the 30 minute recording or afterwards when you play it back.