Reviewing Audio

[Slats]

G'day All
This is for my fellow "audiophiles".
I have found whilst reviewing audio that if I scrub through the file I am able to get far better results than if I skip through to louder sections of the file.
Using wavepad (Rusty I'm too cheap for Isotope RX lol) I press play and then fast forward through the file, if anything catches my attention I quickly go back and listen to it at normal speed. I then log the time stamp for further review later. It is horribly slow at about 4-5 hours for 24 hour audio file but it's the only way I'm able to get results.
To the other researchers using audio recorders, how do you review your files?

Cheers Slats

[Rusty2]

I press play and then fast forward through the file

That's twice as quick .
A friend of mine used to listen to each file in real time because he didn't want to miss anything .

[yowiedan]

After looking at the sound spikes countless times you tend to know certain spikes such as planes on the audio recording. But in saying this some of my best recordings hardly spiked when uploaded to Wavepad. So I do go through alot of the recordings just listening and also stretching the spikes out so you can see the smaller spikes easier.

[adventurer]

Hi, i have to admit i just fast forward to the louder sections of the file. I audio a lot and is way to time consuming for me to replay the whole files. With video footage i sit through the whole lot.Ta

[Slats]

Thanks guys
That's the thing, most of my captures barely register on the waveforms or spikes and using the spectogram it doesn't keep up due to the file size.
I've messed around with my latest recordings, this probably why I'm asking others techniques, skipping through to the louder sections and scrubbing through. By skipping through I missed a heap of data I then went back and scrubbed through catching an extra branch breaking and several fox calls.
I guess I was just curious as to others techniques, I realise that experience plays a huge part in recognising different types of waveforms. Just trying to speed up my process somehow, maybe I should stop messing around and just stick to what works for me.....

[rowdy]

I seem to remember I read an article somewhere about audio software and techniques of searching. It may have been a Yowie Times article written by Rusty. Does anyone remember the issue?
I’ve been thinking that I might have a go at writing some software that is able to go through these large audio files and extract areas of interest. Trouble is I don’t really know what to look for. Any ideas on how it might work? I initially thought I could identify the sound spikes and play them in order from loudest down. But then some of the people on this forum are saying that loudness is not so important. Any ideas, please speak up. There must be a better way than listening through many hours of audio.

[yowiedan]

I seem to remember I read an article somewhere about audio software and techniques of searching. It may have been a Yowie Times article written by Rusty. Does anyone remember the issue?
I’ve been thinking that I might have a go at writing some software that is able to go through these large audio files and extract areas of interest. Trouble is I don’t really know what to look for. Any ideas on how it might work? I initially thought I could identify the sound spikes and play them in order from loudest down. But then some of the people on this forum are saying that loudness is not so important. Any ideas, please speak up. There must be a better way than listening through many hours of audio.

Hey, If you go to the August 2017 Issue of The Yowie Times Rusty talks about how to use the programs to find what you have recorded on them In Tips & Techniques. I will upload the Front Cover of The Issue which has this information in it.

[Rusty2]

Hey Rowdy !
Wildlife acoustics has an audio search program called Kaleidoscope . It does what your asking for BUT , it isn't looking for yowies . You can "teach it" to find what your looking for but you have to have the audio examples first so it can learn what to look for . It also costs an arm and a leg , $560 a year for the subscription .
https://www.wildlifeacoustics.com/produ ... oscope-pro
Izotope RX7 is awesome in my opinion . It has saved me a lot of time and is capable of enhancing and repairing audio which is what you also need . With this program you can SEE the various noises and vocalisations that your looking for without having to guess . The thing is , there are subtle noises and distant calls which you may very well miss . If you use a program like Kaleidoscope it will miss something and that something may be a very important call . Izotope allows a quick and thorough search of audio files . Around 30 minutes for a 6 hour file . $420 single payment to own it . A warning with this one , it will crash if you PC can't handle it .
https://www.izotope.com/en/products/rep ... /post.html

[AL Pitman]

I have no idea on this topic
But if you use an enhancement program to modify audio or video doesn't that compromise the validity of the data ?

[Rusty2]

if you use an enhancement program to modify audio or video doesn't that compromise the validity of the data ?

Yes and no , technically yes , but it depends on what your doing . Enhancing a vocalisation will degrade the original quality or context of the vocalisation but it all depends on how much enhacement is used . Reducing surrounding noise won't enhance a vocalisation but will help seperate or isloate it for better listening . Atomospheric conditions can play a part . Some vocalisations at night can be enhanced without losing the context of the original and some can't because of wind or other ambient noise .

Discretion must be used when enhancing audio . Less is best . Low quality audio recordings have less information to play with or adjust . Unless it's a good recording , vague calls or vocalisations can be very difficult to enhance without losing the context (?) of the original recording .

Good quality audio recorders collect much more information and can be enhanced more because of the amount of information . If it's a good recording there is usually no need to enhance the actual vocalisation but noise reduction can be applied to help isolate a call or vocalisation .

From my experience , boosting certain frequencies can enhance audio without degredation .

[AL Pitman]

It would only make sense to disclose any enhancement software utilised so as to negate the fake sayers .
I guess even speaking through a microphone is an enhancement of the original albeit it does not change the message that is delivered.
Thanks Rusty CHEERS

[Rusty2]

It would only make sense to disclose any enhancement software utilised so as to negate the fake sayers .

Consider it done .

I guess even speaking through a microphone is an enhancement of the original albeit it does not change the message that is delivered.

That's right . Every piece of audio I've ever put online has had some form of enhancement .
One of the first things I do is increase the volume . I then usually use noise reduction and then possibly an EQ adjustment . Any other adjustments are usually minimal .
A tell tale sign of over enhancement is a watery type sound .

Thanks Rusty CHEERS

No problem !

[rowdy]

Thanks for all your replies. It looks like there's a few very capable and professional audio analysis products on the market. I couldn't hope to compete with any of these. I thought I would try to develop something that was useful for yowie research that could do a bit better than the free software already available. Of course it would be free too. It would be more a tool for searching audio files - not so much audio processing. I'll see how I go over the next few months. I might get stuck in the early stages as I haven't developed any audio software before. Once I get past the basics, I will probably ask for ideas on program features from everyone.

[Slats]

Thanks for all your replies. It looks like there's a few very capable and professional audio analysis products on the market. I couldn't hope to compete with any of these. I thought I would try to develop something that was useful for yowie research that could do a bit better than the free software already available. Of course it would be free too. It would be more a tool for searching audio files - not so much audio processing. I'll see how I go over the next few months. I might get stuck in the early stages as I haven't developed any audio software before. Once I get past the basics, I will probably ask for ideas on program features from everyone.

Hey Rowdy
That sounds awesome if you could do something like that. I'm still pretty slow at reviewing audio hence the reason I created this thread. ATM it takes me 5-6 hours to review a 24hr file. I scrub through at 5x the speed and I play at normal speed to review any anomalies.

I use Wavepad (the free download) it's pretty good and thinking about what rusty said about 6 hour file I am contemplating splitting the original 24hr file into 4 to make it easier to work with allowing the computer to handle it easier.

[Slats]

I have no idea on this topic
But if you use an enhancement program to modify audio or video doesn't that compromise the validity of the data ?

Hey Al
I don't do much more than amplify the file. I really dislike the "watery" sound Rusty mentioned. It's important to keep the original file so it can be shared if requested.
As I'm reviewing the file I log the time stamp and small note of what it maybe I then copy the section and make adjustments from there.

[AL Pitman]

Hi Slats
I would never doubt your integrity or the material that you post .
I have been to trustworthy in the past and I feel that it has left me on the outer .
I enjoy listening to the audio posts some of which are very credible and descriptive , if only they had the vision to go with them Lol.
I have been out around my heavily timbered
farm this Easter weekend and not even a footprint to crow about despite living in an area that could be considered hot .
Oh well they are seasonal visitors I suspect I can expect to see more action as the winter approaches as I live in lower country and I reckon that they come down from up in the mountains to escape the more extreme cold .

[Slats]

Hey Al
I have trusted someone's word in this field only to find out it was all lies aswell, it's an unfortunate situation when people feel they have to make stuff up....
I reckon they're somewhat nomadic aswell following the food and water but within a home range similar to the aboriginals. The size of the home range is the big question.

Cheers