Surround-sound recording using a floating array. 4 x H2a-XLR Hydrophones recording directly to a Tascam DR-70D. All files original recorded at 96Khz 24 bit and downstreamed to a portable mp3 320. For higher quality files contact me directly. For the most part these audio files will stream out as stereo. For surround-sound right click and use "Save Link As" to download the surround-sound versions - this assumes you have correctly installed a local surround- sound audio card. Believe me - it is worth it!
The ambisonic recordings were captured to the Tascam 70d in Format-A. They were then manipulated through the SPS200 software to a 5:1 matrix. Ambient recordings can be tuned using a positive notch filter of the type below.
The Sound of Kilmaleau - Recorded September 2015. Natural marine recording manipulated by selective notch filters to produce a "chord".
Sanna Bay 56442561118 - Recorded September 2015. Natural marine recording. The crackling noise is produced by the hole in the wall gang of the ocean floor - snapping shrimps!
Sanna Bay Bio Music - Recorded October 2015. Sounds from Sanna Bay - surf, walking on shells, water tank and pipe hits and a musical bridge squeek.The music's three chords are produced by filtering the hydrophonic recordings made in the bay.
Lighthouse Bio Music - Recorded October 2015. The note sequence and sine sweep is taken from admiralty charts "Arc of Visability" for Ardnamurchan point. At a fixed radius the light sweeps across the sea bed and plays an inverted topographical scale every 20 seconds.
Minke Programme - Production Notes available here
Otter Programme - Production Notes available here
Porpoise Programme - Production Notes available here
Seal Programme - Production Notes available here
Compositional Methods
Biomusic is a form of experimental music which deals with sounds created or performed by non-humans. The definition is also sometimes extended to included sounds made by humans in a directly biological way.
Biomusic can be divided into two basic categories: music that is created solely by the synthetic animal (or in some cases plant), and music which is based upon synthetic animal noises but which is arranged by a human composer. Some forms of music use recorded sounds of nature as part of the music, for example New Age music uses the nature sounds as backgrounds for various musical soundscapes, and ambient music sometimes uses nature sounds modified with reverbs and delay units to make spacey versions of the nature sounds as part of the ambience.
The music for the project is a combination of ambient in situ recordings enhanced with the scientific data provided below and combined with synthesis. This provides each programme a musical bed which will be manipulated by the more traditional compositions and instruments.
Optional Variables
Tide: Expression,
Current: Dynamics
Water Depths: Melody
Light Sequence: Tempo
Definitions:
Tide Data drawn from the National Oceanography Centre, Liverpool. NTSLF Format. Yearly figures for surface elevation minus residual provide a range of values expressed on a musical scale from Pianississimo to Fortississimo.
The Integrated Ocean Observing System (IOOS) includes an array of moored and drifting buoys that measure SST and near-surface currents throughout the world’s oceans. The speed and direction data is transcribed to provide a dynamic (volume) map for each musical piece
Water depths and ocean topography throughout the effective range of the lighthouse provide a note sequence with the sweep timing taken from Ardnamurchan light sequence.
Convolution Reverb
In audio signal processing, convolution reverb is a process used for digitally simulating the reverberation of a physical or virtual space. It is based on the mathematical convolution operation, and uses a pre-recorded audio sample of the impulse response of the space being modelled. To apply the reverberation effect, the impulse-response recording is first stored in a digital signal-processing system. This is then convolved with the incoming audio signal to be processed. The process of convolution multiplies each sample of the audio to be processed (reverberated) with the samples in the impulse response file.
Real space simulation: The primary goal of a convolution reverb is to sample real spaces, in order to simulate the acoustics of the sampled space. A straightforward and simple mono example of capturing an impulse response would be to set up a microphone in a concert hall and to place the microphone in the centre of the auditorium. Next, produce a very brief pulse (often an electric spark) of sound, and record everything that the microphone picks up, which includes both the original sound and the response of the room to it. The recorded take would then be cleanly edited and loaded into the convolution processor. This convolution can be applied as part of a signal processing chain.
Ardnamurchan Lighthouse was convolved using both a sweep signal and starter pistol. A Soundfield SPS200 was used for capturing the impulse and then processed through Voxengo Deconvolver. It was stored and inserted into the audio chain using Waves IR1 Plug in.
Hydrophonics
Just as microphones are used to listen to sound in air, devices called hydrophones are used to listen to sound underwater. Microphones convert sound in air into electrical signals. The electrical signals can then be amplified, recorded, played back over loudspeakers, and transmitted over telephone lines. The electrical signals can also be used to measure the characteristics of the sound, such as amplitude and frequency. Similarly, hydrophones convert sound in water into electrical signals that can be amplified, recorded, played back over loudspeakers, and used to measure the characteristics of the sound. Hydrophones listen to sound, but do not transmit any sound.
Humans were listening to underwater sounds with air tubes as early as 1490, when Leonardo da Vinci wrote about it. It wasn't until the mid to late 1800's that the technology was developed to convert acoustic signals into electrical signals, however. This technology advanced enough that by World War II, British, French, and American scientists were using echo-ranging to locate icebergs and submarines. The ability to locate submarines was invaluable against the German U-Boats.
Most hydrophones are made from a piezoelectric material. This material has a special property that allows it to produce small electrical signals when squeezed, that is, when it is exposed to pressure changes. Because sound is a pressure wave, it can be detected by a piezoelectric element. Under the pressure of a sound wave, the piezoelectric element flexes and gives off electrical signals.
These electrical signals can be recorded and later analysed with computer programs to determine the properties of the sound wave, including amplitude a Some hydrophones, called omnidirectional hydrophones, record sounds from all directions with equal sensitivity.
Other hydrophones, called directional hydrophones, have a higher sensitivity to signals from a particular direction. Directional receivers are most often constructed using a number of omnidirectional hydrophones combined in what is called an array. Directional hydrophones are typically used in systems for locating and tracking objects and frequency.
Hydrophones are specially designed for underwater use. They are normally encased in a rubber boot to provide protection from seawater. Hydrophones can be mounted in several different ways. They can be attached to a boat, towed, or placed in a fixed position underwater.
Sanna Bay was recorded using a floating rig measuring 2m sq. Each of the four microphones were attached at the corner posts and floated at three seperate depths at each location.
