Avisoft-RECORDER

The new dimension of PC-based Multichannel Triggering Harddisk Recording

Avisoft-RECORDER is a versatile multichannel triggering harddisk recording system. It was designed for the special needs of bioacoustics, but it can also be used for any other audio signals. Possible applications are:

Long-term monitoring and recording of acoustic events both in the laboratory and in the field.
High-speed harddisk-recording with sampling rates up to 1 MHz* with various data acquisition boards (Avisoft-UltraSoundGate, National Instruments, Data Translation, Measurement Computing (formerly ComputerBoards), ines) and soundcards (up to 192 kHz).
Pre-trigger recording of sporadic animal vocalizations in the field (either manually or automated using one of the various triggering options : threshold / manual / digital input / timer / ... ).
Individual triggering and saving of single channels from multichannel soundcards or data acquisition boards.
Multichannel real-time spectrographic display.
Real-time acoustic monitoring of ultrasound signals by using heterodyning or aliasing technique.
Real-time frequency measurements, that can also be issued by voice messages.
Recording front-end for Avisoft-SASLab Pro.
Playback with both standard soundcards and high-speed output streaming devices.

* The maximum sampling rate for real-time display and streaming to disk depends on the type of acquisition board and computer performance (USB, PCMCIA or PCI board, processor speed, graphics adapter, disk transfer rate, ...)

Avisoft-RECORDER screen shot Data flow scheme

Avisoft-RECORDER screen shot

configuration diolog box

Up to 8 channels, each sampling at up to 1 MHz can be monitored simultaneously. Each channel can be triggered separately by different trigger events. An trigger event can be the exceeding of a certain energy threshold within a pre-defined frequency interval. This mechanism prevents triggering caused by undesired disturbance signals outside the frequency range of the animal vocalizations. Additionally, an entropy parameter can be used to discriminate between noise and pure-tone signals. For more sophisticated signal filtering, the Avisoft-SASLab classification facility may be used.

Alternatively, trigger events can be keystrokes, joystick button hits or timer intervals. Once a trigger event has occurred, the assigned channel(s) will be written into numbered WAV-files onto the hard drive as long as the trigger event is active. In order to capture sounds preceding the trigger event, a pre-trigger duration can be specified. Additionally, a hold-time can be defined to prevent cutting up of related sound elements. See the principle of sound-activated recording for more details.

The created event files are time-stamped (at sample clock resolution) enabling subsequent re-assembling into larger continuous files for precise temporal analysis. Sound-activated recording can be restricted to user-defined periods of (day-) time.

The adapted Avisoft-SASLab Pro sound analysis software and the LOG-file output support quick navigation through the captured sound files. For single-channel applications a special low-cost version is available.

Both standard soundcards and high-speed output streaming systems (National Instruments DAQCards) can be used for playback of .wav files with the integrated playback feature. For ultrasonic playback experiments, an appropriate power amplifier and speaker can be provided. Playing a .wav file can be initiated simply by dragging the desired file into the RECORDER application window. There is also a powerful play list feature enabling automated playback of long file sequences. Several sound files can be selected into a play list that defines the playback sequence. The play list is constructed by simple drag&drop operations. A loop option enables long-term playback. A "randomize" option allows playing the selected files in a random sequence. The playback features can be used in parallel and independent from the recording mode of Avisoft-RECORDER.

play list screen shot

System Requirements

IBM-compatible PC, Pentium running at 133MHz or more
At least 16MB of RAM, 32MB or more are recommended
Harddisk space: > 2GB, depending on the amount of sound files to be captured
VGA-Display with at least 256 colors
Soundcard compatible to Windows (MCI-driver required), Avisoft-UltraSoundGate or data acquisition board by National Instruments (e.g. DAQ Card 6062E), Data Translation (e.g. DT303), Measurement Computing (e.g. PC-Card-DAS16/330) or ines (e.g. DAQ-PCMCIA i508)
Operating system: Microsoft-Windows95/98/ME or WindowsNT/2000/XP

For more details on the RECORDER software consult the DEMO version with its online help system and the User's Guide.