before 1990 |
I became interested in pitch analyzing when my wife
Stefanie Stadler
Elmer worked on her PhD thesis about pitch singing quality
of young children. She analyzed here audio tapes by ear with the
help of an automatic tuner (KORG AT-12). Such a device is
usually used to tune musical instruments. This can be done
either traditionally by ear or automatically with a built-in pitch
analyzer. In the first case the tuner produces a tone of
a well-defined pitch. In the second case it analyzes the sound
and shows the pitch by an LED on a chromatic scale. In addition
a needle on an analog scale shows the deviation in cent.
Analyzing audio tapes with this automatic tuner was very cumbersome
because the events are so short and the tuner wasn't
able to freeze or to store the pitch for better reading.
Thus I started to look for a better technical solution.
|
1990 |
I bought for our computer (an ATARI ST1024) an 8-bit sound
sampler (hardware and software) and I read the monography
of Hess (W. Hess:
Pitch determination of speech signals:
Algorithms and devices. Springer Verlag, 1983) in order
to get some ideas about extracting the pitch from
sound data. Then I started to develope an analyzing tool for
the ATARI ST. But this project was interrupted
because I got a research grant and we spent a year in San
Diego. Back from the States I didn't continue this
project because our kids absorbed all the energy of my wife.
|
1994 |
Our kids had become older and my wife had been resuming her
research on children's singing. Now she had here own
PC (Intel 386, 40 MHz, sound card, Windows 3.1).
Thus I developed a pitch analyzer for Windows 3.1 instead for
ATARI ST.
I wrote the application in C++ by using Borland's
OWL library for the graphical user interface.
The application used a simple time based algorithm (the same
now used in the analyzer 'Minimum Maximum Analyzer') using only
integer arithmetics. The result had been shown
graphically (superimposed with the data) and numerically.
Because this tool was not able to record audio data or to
navigate through the data, we used a commercial
sound editor (CoolEdit V1.34) for these purposes.
The analyser gots the data from the editor via the scratch pad.
In the following years this pitch analyzer had become the
working tool of my wife. Without this tool she wouldn't
been able to get all her important results about the
singing development of children. There was growing interest
by other researchers in using this tool.
|
1999 |
In July 1999 I decided to write a completely new pitch
analyzer. I thought it would be a nice idea to develop
a version which is independent from
- an additional sound editor,
- the computer platform, and
- the type of analyzing algorithm.
|
2001 |
In January 2001 I published the Pitch Analyzer (V1.1) on the
Web as a free tool.
|
2006 |
During the years I got only little response on the published
application. But at the end of 2005 and the beginning of 2006
more and more colleagues of my wife used or wanted to use
the Pitch Analyzer. But they are faced with some problems and bugs.
Therefore I decided to overhaul the Pitch Analyzer. No features
has been added but now it needs Java Runtime Environment 1.4.2.
The advantage is that no tricks with audio playing are necessary.
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