HASA is a handheld audio frequency spectrum analyzer for the Pocket PC. Frequency components of sounds picked up by the built-in microphone are shown and analyzed in real-time. The frequency decomposition can be shown as a standard plot of dB vs. Hz or as a "cascade" plot, showing its time evolution. The standard plot can be shown as a line or ISO bar chart. For checking purposes, an artificial White Noise signal can be applied to the Fourier Transform (yielding a flat frequency response). The user may choose to average the frequency response data over an extended period of time, and exclude a region of the measured time data in order to remove any observed transient anomalies that may appear. Clipping at the microphone is indicated on the HASA display, as are the real-time measured samples and their frequency spectrum.

The measured spectrum can be A-Weighted, and can be stored as a file in the PocketPC. Stored spectra can be loaded at run time, and subtracted from the current spectra in order to correct the data. A built-in oscillator generates pure tones across the full audio spectrum, or can generate White Noise for frequency response measurements etc.. Another included feature is note detection, where the equivalent piano note on the equal-tempered scale is detected from the measured spectrum. This in principle allows a quick determination of whether a musical instrument is badly off tune or not...

A full installation and user guide is included.

Possible Applications:
Measuring sound levels in a car, plane, room, rock concert etc..
Measuring the frequency response of audio equipment, e.g. loudspeakers
Measuring frequencies and levels of noise from equipment.
Measuring fidelity of home or car audio systems (e.g. using the built-in White noise generator, or a test CD).
Measuring frequency of an opera singer's top A!
HASA supports Pocket PC (MIPS & SH3) as well as Pocket PC 2002 (ARM) devices, including the new XScale CPUs
See the HASA.html file in the download kit for further details.

Requirements:

· Color Pocket PC or Pocket PC 2002, 1 MB available RAM