Do NARs (network audio recorder) exist?

O

oh6hfx

Getting the hang of it
Jun 26, 2016
172
53
Lohtaja, Finland
A customer is living middle of the forest and is interested in nature sounds. The last one was strange bang that was coming probably when ground was freezing, temp dropping rapid below -10c. One of his ip-cameras has built-in mic so we searched the noise there, could find it when exported .wav to Audacity and looking the waveform. However,
the quality was poor, Dahuas strong compression/noise reduction making everything sound digitalized, so no big help.

I wonder if there are separate devices to record good quality audio on hard disk and control it via network?

I know there is plenty of audio recorders for music/video/broadcast production, but I mean more a surveillance-centered, just like a NVR but just recording audio, 24h, wiping over oldest recordings, maybe marking audio peaks over threshold on timeline, etc.

I also know that I can hook a good mic in an IP-camera, but still the quality is not that good. Also I haven't yet seen a NVR which has good search options for audio. Can't see waveform to find small peaks over noise, etc.

Of course also a good wind protection for the mic is important, and it is not so easy to do when the mic should be exposed outdoors. Fur "deadcat" gets wet, and if it is under roof, it gets the rain noise from the roof...

Any ideas?
 
So not sure this helps but, If you have the Audio Filter on in an IP camera the audio is reduced. So I would turn off the Filter. Second the NVR and cameras both can normally record what is different in audio. Some tweaking will be needed to meet the needs of the end user but I know that one of my cameras that has very little video time because the area isn't used much I do get a good few alerts for audio because it picks up things that happens from outside. Like the door slams in the Vehicles. I know that if there is this alert and a Tripwire that it is more then likely my son or brother leaving. If there is that sound and no other alerts then I know I should check other cameras around because something might be going on that is out of the Events portion of the cameras but still enough to be detected in the audio portion of that camera. Like right now it is high winds so there is some chatter that is picked up form branches or other things that are making that audio alarm activate. It records to a Recorder and I can also playback. Now if it was just for audio, i would put camera on full time sub channel record with audio enabled for both sub and main. Then when an event happens you can play back in times before and after that event to see if there is more that might not got picked up but was enough to be detected and recorded in full time recordings..
 
Thanks Revo2Maxx. In some Dahua cameras it is not possible to turn off noise filter. Also the bitrates for audio are quite low, so in any case the audio sounds too compressed. There also is possibility for audio trigger as an IVS event, but normal IP camera built-in mic gets wind noise very easily and triggers it right away.
 
I don't know, I have loads of Dahua and there OEM cameras from has far back as 2010 and all of them have the ability to enable or disable the noise Filter and most of them have the ability to change Audio format to something like ACC that can go up to 64000.. I mean .

However don't know the budget but here is some other ideas that might work out for you..

Wildlife Acoustics Song Meter Mini / Song Meter Micro like the SM4
Tascam DR-05X / DR-40X
Zoom H2n / H4n Pro
AudioMoth
Network Audio Recorders (Like Axis Audio Recorders) Ip based solution kind of like NVR, can work with IP mics Motion and Audio triggers.
Raspberry Pi + USB Mic and Sound card for DIY solution..
 
Revo2Maxx said:
I don't know, I have loads of Dahua and there OEM cameras from has far back as 2010 and all of them have the ability to enable or disable the noise Filter and most of them have the ability to change Audio format to something like ACC that can go up to 64000.. I mean .
Click to expand...

You are right. Checked quickly two cameras, basic IPC-HDBW2241E-S has only 16000 on AAC and PCM, but IPC-HDW3849H-AS-PV has even 64000. I can't recall the model now, but there was one Dahua camera that after fw update had noise filter all the time on, no ability to turn off.

Revo2Maxx said:
However don't know the budget but here is some other ideas that might work out for you..

Wildlife Acoustics Song Meter Mini / Song Meter Micro like the SM4
Tascam DR-05X / DR-40X
Zoom H2n / H4n Pro
AudioMoth
Network Audio Recorders (Like Axis Audio Recorders) Ip based solution kind of like NVR, can work with IP mics Motion and Audio triggers.
Raspberry Pi + USB Mic and Sound card for DIY solution..
Click to expand...

Thanks, these are all good audio recorders - I myself have Zoom H2N and Zoom H1N, but they are stand alone units recording on sd cards. Network audio recorder is the one I'm looking for. I was thinking about PC + suitable software or then Raspberry Pi like you mentioned too. Have to do more research...
 
oh6hfx said:
A customer is living middle of the forest and is interested in nature sounds.
Click to expand...
Side thought:
Bird sounds in particular? Or Bat sounds?
BirdNET AI engine might be of interest to them.
It identifies bird calls, then identifies the species of bird. Can be microphone connected directly or RTSP stream (aka IP/network).
Then records to the device upon detection.

Device can be a mini PC, or Raspberry Pi. If you use a Raspberry Pi, I suggest an SSD/HDD rather than burning out the SD card.
BirdNET-Pi has tutorials online for setup. There's also BattyNET-Pi for bats.
BirdNET-PI



I've heard some people use extra Raspberry Pi's just to take a USB mic and output RTSP audio stream too.

My IP audio setup:
Behind a spoiler so Google doesn't index these images.

My BirdNET-Pi instance running. I was using a SD1A404XB-GNR, but now that camera has been replaced by a DH-IPC-HDW3849H-AS-PV.
The DH-IPC-HDW3849H-AS-PV with audio filters OFF and in AAC 32k seems to still have a noise suppression above 8.5kHz.

BirdNET-Pi cannot handle above 32k AAC.

1742728330714.png
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BirdWeather also sell a ready-made device, BirdWeather PUC, but I believe this requires an internet connection and off-loads all audio to the cloud for processing (it runs off an ESP32).
www.birdweather.com

Shop BirdWeather PUC

www.birdweather.com www.birdweather.com
1742728652966.png
 
Thanks Mark! That's a good tip. It's not bird sounds, just everything you can hear outside. Birds, animals, ambient noise, gunshot, chainsaw, horses passing. Like a good quality audio surveillance, you can just keep on all the time and then check if for example you hear something inside the house but are not sure what that was.
 
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