That was the line my late grandfather in law, may he rest in peace, would say often as he lived to his 90s. "It is hell getting old...."
A few days ago I was preparing a wav file that represents the jitter test signal: J-Test. This is an 12 Khz tone that has a tiny squarewave riding on it. I googled and googled forever and it was near impossible to find this test file! You would think this test file is on some file server but no. Eventually I find a program that generates it. Alas, the program was compiled long time ago and would not run on my Windows 7 machine even in compatibility mode. The source code was provided but it would not compile in recent versions of Visual Studio (program development tool from Microsoft).
After a day of debugging, I finally get it working. I double click on the media player and it accepted the file and started to play it on my laptop. I could not hear it at the default volume so I pull it into my audio editing app and see the waveform is there. With lots of joy, I burn a CD and go and test it with my analyzer in my lab downstairs.
Then my 19 year old son shows up worried saying, "Dad, the hot water heater alarm has gone off." I have this moisture detection alarm in our HVAC room where it has saved our bacon multiple times by going off when it detected leaks. So I rush there and open the door. There is no water. And I do not hear the alarm. I ask my son what he was talking about. He says he is still hearing the same kind of tone.
I go upstairs and my wife says she is is also hearing it. Of course I hear nothing. We start to search the house to see what alarm may have gotten off. Right then both say it stopped. Then I remember that the test CD I had built had 10 copies of the one minute J-test track so it would have been running for 10 minutes on my laptop in the living room and then stop. I start the player again and both say they can hear the high pitch sound. Well, I could not at all. But at least the mystery was solved.
Mind you, this is from my laptop with tiny speakers and at some low level. So likely I can still hear 12 Khz. But boy, compared to them I am pretty deaf. It sure is hell getting old....."
A few days ago I was preparing a wav file that represents the jitter test signal: J-Test. This is an 12 Khz tone that has a tiny squarewave riding on it. I googled and googled forever and it was near impossible to find this test file! You would think this test file is on some file server but no. Eventually I find a program that generates it. Alas, the program was compiled long time ago and would not run on my Windows 7 machine even in compatibility mode. The source code was provided but it would not compile in recent versions of Visual Studio (program development tool from Microsoft).
After a day of debugging, I finally get it working. I double click on the media player and it accepted the file and started to play it on my laptop. I could not hear it at the default volume so I pull it into my audio editing app and see the waveform is there. With lots of joy, I burn a CD and go and test it with my analyzer in my lab downstairs.
Then my 19 year old son shows up worried saying, "Dad, the hot water heater alarm has gone off." I have this moisture detection alarm in our HVAC room where it has saved our bacon multiple times by going off when it detected leaks. So I rush there and open the door. There is no water. And I do not hear the alarm. I ask my son what he was talking about. He says he is still hearing the same kind of tone.
I go upstairs and my wife says she is is also hearing it. Of course I hear nothing. We start to search the house to see what alarm may have gotten off. Right then both say it stopped. Then I remember that the test CD I had built had 10 copies of the one minute J-test track so it would have been running for 10 minutes on my laptop in the living room and then stop. I start the player again and both say they can hear the high pitch sound. Well, I could not at all. But at least the mystery was solved.
Mind you, this is from my laptop with tiny speakers and at some low level. So likely I can still hear 12 Khz. But boy, compared to them I am pretty deaf. It sure is hell getting old....."
