special topic 1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Special Topic 1 PowerPoint Presentation
Download Presentation
Special Topic 1

Loading in 2 Seconds...

play fullscreen
1 / 9

Special Topic 1 - PowerPoint PPT Presentation


  • 123 Views
  • Uploaded on

Special Topic 1. Processing Sound Files The most interesting sounds are those which have sine tones. Record Sound with Your Device. For Android Users. Allows sound recordings to be transferred in *.ogg format via Email. Similar apps appear to be available to iPhone & Apple Devices.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Special Topic 1' - purity


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
special topic 1
Special Topic 1

Processing Sound Files

The most interesting sounds are those which have sine tones

for android users
For Android Users

Allows sound recordings to be transferred in *.ogg format via Email.

Similar apps appear to be available to iPhone & Apple Devices

audio file formats
Audio File Formats

There are many types of formats. Common ones are:

*.mp3 - MPEG Layer III Audio - compressed format - popular for CDs

*.ogg - Ogg Vorbis - open source - compressed format - Archos and Samsung

*.wav - large file sizes, convenient for conversion to ASCII text

http://en.wikipedia.org/wiki/Audio_file_format

conversion
Conversion

Need data in *.wav format for digital post-processing

Use conversion utility such as:

  • Online conversion:
  • http://www.zamzar.com/
  • Download freeware audio editor:
  • http://audacity.sourceforge.net/
matlab utility
Matlab Utility

vibrationdata > Miscellaneous > Sound File Editor > Read wav File

Read wav file then Export to Matlab (one or two channels)

sample sound file two channels
Sample Sound File, Two Channels

Read into Matlab. Then Export to Workspace

File: crj900.wav - noise inside aircraft cabin due to engines, etc.

fast fourier transform
Fast Fourier Transform

Each turbofan engine has two rotors.

N1 Fan - 104 Hz

N2 Core - 252 Hz

Engines were at 85% power for this recording.

vibrationdata > FFT - input one of the sound channels