iSTETHOSCOPE PRO

undercover scientist software

Instructions:

Press play or wait a second to see the stethoscope, then press the mode button to choose the listening mode. The program starts up muted by default. Check out the images below to see where to place the microphone, and where the microphone is. (Please note that the microphone for the iphone 4 is on the BOTTOM LEFT of the device. The microphone for previous iphones was on the bottom right.) Make sure the microphone is pressed directly against your skin - it cannot hear even through a thin shirt. [If you are an iPod Touch user with no extra microphone, then press the little microphone symbol to the left of the volume. When you see a red X (meaning no microphone) press "mode" to start the audio in compatibility mode.]

The first time the program runs, you will see a message: "iStethoscope Pro has not been activated. Please quit, go to Settings, and activate the application." You must then quit the program, find and run the Settings application, scroll down to see iStethPro, touch Activate and select "on." Please read and agree to the message in the activation setting, it is there for your safety. The program will not run until you activate it. When activated, the next time you run the program and press "mode" the activation window will disappear.

WARNING! Do not place your phone over your heart if you have a pacemaker or implanted defibrillator fitted. If you are concerned about radiation near your heart, put the device into "airplane mode" before running iStethoscope Pro.

You can adjust the volume by using the normal volume buttons on the side of the iPhone, and make further changes to the gain of the amplifier by moving the slider at the bottom of the screen. It's best not to have these on maximum. To protect your ears, the program activates Automatic Volume Control (avc) if the sound is too loud - remember the point of a stethoscope is to hear very quiet noises near to the microphone. AVC immediately fades away when all is quiet again.

Things to try:

- Give your iphone a shake and replay the last eight seconds while watching the phonocardiograph and spectrogram displays. Try zooming in by adjusting the spectrogram scaling in the Settings.

- In "Accelerometer" mode, lie down, place the iphone on your chest (against bare skin), hold your breath, and see if you can hear the tiny vibrations of your heart. (Higher pitched tones mean bigger vibrations.) Try improving the accuracy by using a smaller accelerometer update rate. Use the spectrogram to see the changes in G forces.

- In "Conversation" mode amplify the voices of your friends around you in real time, with no noticeable delay. Try adjusting the delay in the Settings and improving the clarity by tweaking the filter and amplify settings.

- Use good quality ordinary headphones in "Heartbeat pure" mode, and place the bottom of a 3G iphone against your chest to hear the deep thuds of your heart in wonderful clarity (you may need to remove it from its protective case if you use one). If you want to know where to listen, take a look at what the experts say: http://sprojects.mmi.mcgill.ca/mvs/CARDIO01.HTM

- In "Heartbeat pure" mode, record 8 seconds of a heartbeat and email it. You will be able to play the attached audio file and see the spectrogram from your iphone Mail program. On your main computer, try renaming the .caf file as .aif and importing it into Audacity where you can analyse the data more thoroughly. (You may find you obtain the best quality data with a sampling rate of 11025 and slightly modified filter values.)

- Wear iStethoscope with a friend, in "Clear Sound" mode, and hear each other talk even when you whisper too quietly for other people to hear.

- Birds nesting in your wall? Trying to trace the path of a waterpipe? Wondering if a quiet harddisk is in use? Try using iStethoscope Pro to amplify and trace the noise!