Further audio analysis techniques

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Steve Smith
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Further audio analysis techniques

Post by Steve Smith »

We often talk about “New Feature Requests” when handling customer feedback and technical support queries. In a nutshell, PicoScope is constantly evolving and trying to keep pace at times is challenging (I am thinking predominately of PS7 at present)

NVH is another example where New Features are being requested and of course “queued” for development along with other requests.

Spectrograms/Heat maps are one such new feature request that will eventually make into our NVH software but in the interim, there are other audio analysis software packages that provide a number of niche analysis features that Ben and I use when handling NVH cases

Sonic Visualiser and Audacity are both exceptional examples of such software and both focus on the manipulation of sound which you may rightly think is beyond the realm of automotive applications.
However, take a look at the video below where I have exported our NVH sensor data in .wav format and then analyzed further with Audacity
FIAT CLUTCH TEST.mp4
Video 1
(12.85 MiB) Downloaded 76 times
I hope this helps, take care……Steve

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PicoKev
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Re: Further audio analysis techniques

Post by PicoKev »

Sorry Steve but I have to disagree with your diagnosis on this occasion.

You have conclusively proved that the issue is a duck tapping a wooden spoon on the inside of the bell housing. :lol: :lol: :lol:

Hope you and yours are surviving the strange times we live in. 8)

Kev.

Steve Smith
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Re: Further audio analysis techniques

Post by Steve Smith »

The more I played that audio back the more it reminded me of old bed/mattress springs, which is another discussion entirely!

We are marching on here, I have no doubt you are too

Take care.....Steve

dtalastas
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Re: Further audio analysis techniques

Post by dtalastas »

If you had a nicer audio program such as Ableton live, pro tools or logic, you could set up quantization blocks and see if those audio waveforms line up. Now say if you had a rattlein the car could I record it even with my iphone and isolate the frequency of the the rattle and use a audio signal generator or pink noise at the same frequency to make that rattle vibrate in the bay?

Steve Smith
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Joined: Sun Aug 25, 2013 7:22 am

Re: Further audio analysis techniques

Post by Steve Smith »

Hello and thank you for posting

I have to admit I had to Google "Quantization blocks" and here I have some questions

I like your suggestion of customers capturing noises on their phones (when safe to do so) and where these noises can be heard within the cabin.

We have discussed a similar technique here topic21962.html

Please forgive my lack of interpretation when it comes to "Quantization blocks".

If I have understood this feature correctly, we are applying a Band Stop feature (to the mobile phone recording) to identify the offending frequency at which the cabin/component is rattling?

For more information on Band Stop the following forum post will help topic14151.html

In order to use the Band Stop feature, we need to import the audio (mobile phone recording) into NVH and we describe in this process here post93381.html#p93381

If the above is correct, using Band Stop highlights the offending frequency of interest which we can then playback into the cabin?

Could you confirm if the above process achieves the same end result as "Quantization blocks" using the Ableton Live software?

It would be great to learn an alternative method if you could share here?

Thank you again for posting and take care……Steve

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