USB ultrasound acquisition interface for mobile high-speed harddisk recording

Key features

• Portable harddisk recording at sample rates up to 750 kHz with adaptive anti-aliasing filter,
• Avisoft-UltraSoundGate is a turn-key system which comes complete with ultrasound microphone, cables, rugged USB-based data acquisition hardware and harddisk recording software (and optional analysis software),
• Optionally, high-performance phantom-powered condenser microphones (e.g. SENNHEISER MKH 800 P48) can be connected directly to the models USG 116 P48 and USG 124 P48,
• Direct interfacing to the Avisoft-RECORDER software for real-time spectrogram display(!) with advanced triggering facilities and optionally to the Avisoft-SASLab Pro high-resolution real-time spectrogram display,
• Compatibility to any sound recording application that supports high sample rates (the UltraSoundGate device appears to the PC as a standard audio recording device),
• Acoustic real-time (broad-band) monitor,
• Overload indicator & peak level meter,
• When connecting UltraSoundGate to an extra power supply (disconnected from USB), it changes into a self-contained bat detector for acoustic broad-band monitoring.
• Trigger button for quick start and stop of recordings with Avisoft-RECORDER. That button appears to the PC as a standard joystick button, enabling custom application programming. A digital input line allows to connect external trigger signals (e.g. a remote control button or photo transistor for light-depending trigger enabling). The digital input is sampled and stored at the same rate as the analog input (for acquisition of other custom-specific digital information as serial time-stamp signals (e.g. IRIG-B from a GPS clock) for synchronizing different recording sites),
• Multichannel operation with guaranteed synchronity (Model 416),
• Easy plug-and-play installation,
• Bus-powered operation (no need for extra power-supplies),
• Rugged and compact design suited for field use,
• Watertight, dustproof and unbreakable transport box.

Principle of the UltraSoundGate system

Available UltraSoundGate Models

• UltraSoundGate 112 provides mid-range ultrasound recording (e.g. for rodent vocalizations) at moderate resolutions (12 bit).
• UltraSoundGate 116 allows high-range ultrasound recording (e.g. for bat echolocation calls) at high resolutions (16 bit). The model USG 116 P48 additionally provides phantom feeding for high-quality condenser microphones.
• UltraSoundGate 124 P48 is a general-purpose audio-range and low-range ultrasound recording interface with high-resolution (24 bit). It is optimised for recording both low-frequency audio (e.g. bird song) and lower ultrasonic signals (e.g. grasshopper song up to 80 kHz). It's 24 bit / 192 kHz sampling capability is a unique feature in compact bus-powered USB audio interfaces. The extremely compact size makes it ideal for mobile applications. See also UltraSoundGate 124 P48
• UltraSoundGate 416 provides high-range ultrasound recording at high resolutions (16 bit) and includes four separate channels. See also UltraSoundGate 416.

UltraSoundGate 116

USG 116 connected to a mini-laptop

UltraSoundGate 416, front view

UltraSoundGate 416, back view

Available accessories

• XLR Microphone extension cable (lengths : 2, 5, 10 or 25 m)
• XLR to RCA adaptor cable
• XLR to BNC adaptor cable
• XLR to 1/4'' phone jack adaptor cable
• XLR to 3.5 mm mini-jack adaptor cable
• External trigger switch fitted with a 2.5 mm mini-jack plug
• External foot trigger switch fitted with a 2.5 mm mini-jack plug
• Rugged 2.5 mm mini-jack plug for self-mounting
• External power supply adapter for stand-alone broad-band bat detector mode

System requirements

• IBM-compatible PC, Pentium, 266MHz or more with at least one USB port, running Windows98, Me, Windows2000 or XP. A Pentium III running at 1 GHz is recommended for the multichannel device USG 416. The 24-bit recording mode of USG 124 P48 and the multichannell mode of USG416 is only available from Windows 2000 and XP (WDM driver required).

Example Recordings

The following recordings were made with Avisoft-UltraSoundGate 116 (sample rate 250kHz) in front of the Avisoft office in Berlin, Germany. For compatibilty to common soundcards, the sampling rate of these files was set to 22.05kHz (time expansion of 1:11).

Common pipistrelle (Pipistrellus pipistrellus) echolocation calls
Common pipistrelle approaching an insect (feeding buzz)
Common pipistrelle social call


spectrogram of the social call .wav file created in Avisoft-SASLab Pro

More pipistrelle examples sampled at 214kHz (playback rate 11.025kHz ---> time expansion of 1:20): example4 (152k), example5 (352k), example6 (110k), example7 (239k), example8 (321k), example9 (636k)

Some recordings made during the 12th International Bat Research Conference in Malaysia near the conference venue at the Hotel Equatorial, Bangi (214kHz, playback rate 22.05kHz ---> time expansion of 1:10) : example10, bat (218k), example11, bat (552k), example12, bat (610k), example13, bat (94k), example 14, grasshopper (493k)


The following recordings were made at Bracken Cave, San Antonio, Texas, USA, during the Post Symposium Trip of the Bat Echolocation Symposium organized by Bat Conservation International on 17 April 2002 (originally sampled at 250kHz, resampled down to 220,5kHz and 10-fold time-expanded) : Mexican Free-tailed Bat (688k), Mexican Free-tailed Bat, clutter (173k), Mexican Free-tailed Bat, more clutter (126k).




The song of a bush-cricket (Short-winged conehead, Conocephalus dorsalis) from Berlin-Luebars, Germany (time expansion 1:10).

What are the advantages over common time-expansion devices?

• Real-time spectrogram display during recording,
• Unlimited duration of recordings (only limited by harddisk space),
• No gaps in monitoring (manual transferring of slowed-down sequences onto a tape recorder is not required),
• Simplified analysis because the generated .wav files can be read directly by the sound analysis software (no re-recording of slowed-down tape recordings through soundcard required),
• Automatic frequency-selective triggering for unattended recording,
• Integrated variable anti-aliasing filter,
• Extended dynamic range (resolutions of 12, 16 or even 24 bit),
• Acoustic broad-band monitor,
• Peak level meter for precise recording level adjustment.

Why USB?

System Integration

• Multichannel real-time spectrogram display (0% overlap), waveform envelope display, energy waveform within selected frequency range,
• Pre-tigger harddisk-recording with widely selectable trigger options. Trigger event threshold definition for sound-activated recording can be done graphically by mouse,
• There will be no limitations on the duration of continuous recordings (harddisk space rather than RAM size limits the duration of single recording sessions),
• ASCII-format LOG file containing date, time and duration of each recorded event and optional text comments,
• Manual triggering by the UltraSoundGate button,
• External triggering through the UltraSoundGate digital input (TTL-compatible, 2.5mm mini jack). This external signal can also be used to enable/disable the sound-activated recording mode (e.g. a photo transistor directly connected to the digital input for limiting automatic recording to darkness),
• Multichannel recording with UltraSoundGate 416 with either separate triggering of each channel (separate .wav files for each channel) or simultaneous triggering for all active channels (one single multichannel .wav file containing all channels). The latter configuration is suited for passive acoustic location of animals because all channels are packed into a single data stream, which secures the phase relationship between channels.
• Real-time measurements of call frequencies, that can also be issued by voice messages.
• Real-time acoustic monitoring through the soundcard (heterodyning or aliasing technique).

Avisoft-RECORDER screen shot showing the real-time spectrogram display.


In pre-trigger recording mode, each of the automatically created .wav files contains
one single sound event. A LOG file lists start time and duration of each shot.

• Two-channel real-time spectrogram display (0 - 87.5% overlap*and widley adjustable spectrogram parameters) and simultaneous waveform envelope display,
• The UltraSoundGate button can remote control the transfer of the SASLab Pro real-time circular recording buffer into the main window (in order to quickly capture sound events which were recognized graphically or acoustically),
• Two-channel recording with UltraSoundGate 416,
• Real-time element classification (e.g. for species discrimination) and automatic response generation,
• High-quality spectrogram generation (see a multiple-line spectrogram),
• Advanced offline signal analysis and synthesis.

* The maximum possible FFT overlap depends on the selected sampling rate and the computing power. 256-points FFT with 75% overlap at 300kHz where reached on a SONY VAIO Notebook PCG-Z600TEK running at 700MHz! One of the most critical elements is the speed of the graphics adapter.


Avisoft-SASLab Pro real-time spectrogram display running at 250 kHz with a FFT size of 256 points and 75% overlap.


Avisoft-SASLab Pro off-line spectrogram display with the Automatic Parameter Measurement facility activated


Numeric results of the Automatic Parameter Measurements shown above


For more details on typical applications see the UltraSoundGate / Avisoft-RECORDER Application Notes and the poster on the UltraSoundGate system (1357KB, pdf file format).

Under some circumstances, it would be possible to provide an UltraSoundGate device including software for evaluation purposes prior to purchasing. !

The UltraSoundGate system has been developed by Avisoft Bioacoustics having more than 10 years of experience in designing animal sound analysis software, digital signal processing systems and ultrasound recording / detecting equipment.