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.
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.
Processing Sound Files
The most interesting sounds are those which have sine tones
Allows sound recordings to be transferred in *.ogg format via Email.
Similar apps appear to be available to iPhone & Apple Devices
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
Need data in *.wav format for digital post-processing
Use conversion utility such as:
vibrationdata > Miscellaneous > Sound File Editor > Read wav File
Read wav file then Export to Matlab (one or two channels)
Read into Matlab. Then Export to Workspace
File: crj900.wav - noise inside aircraft cabin due to engines, etc.
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