Dear list members, Just let me explain a little more in detail:Dr.Lennox was right: the clicks were probably due to mic handling, moreover I filtered and amplified the sound because it was really soft.
The sound I want you to pay attention to is the set of very close pulses.All of the recorded sounds have the same structure: they last few seconds (3/4) and they occur "randomly" -one every 10/15 minutes- from 2 to 6 a.m. The aim of the acoustic survey was to monitor another fish species, Sciaena umbra, which made choruses during night in the reproductive period (july and august). This misterious sound started right after Sciena umbra ended the chorus. I add an image with spectrogram and waveform In the same area there are other soniferous fish species: maybe this is a new one - or a common one with unknown acoustic stimuli :)
if it is a machine I am curious to know which one produces a sound like this: in the survey we must distinguish between biological and human sources of noise
thank you very much Linda Quoting "Bruno L. Giordano" <bruno.giordano@xxxxxxxxxxxxxxx>:
I have to agree with Peter: I would be very surprised if this was a biological sound. It sounds too regular and sustained to me, although the 21st century man might have developed a mistaken identification bias to survive in a modern jungle of living agents and evil machines, where seahorses (and woodpeckers) are rare and harmless ;-) Bruno Jazz wrote:Sounds like a Sea-horse, But lots of Fish make similar soundsthere are more to listen to on the websight belowhttp://www.dosits.org/gallery/fishnbay/15.htm Jazz http://www.dosits.org/gallery/fishnbay/15.htm ----- Original Message ---- From: Peter Lennox <P.Lennox@xxxxxxxxxxx> To: AUDITORY@xxxxxxxxxxxxxxx Sent: Thu, 10 December, 2009 10:42:15 Subject: Re: [AUDITORY] Unknown biological soundThere seem to be two sets of sounds - the clicks that sound like mic handling noise aren't at the end, so I'm not sure if they were what you were telling me to ignore. They're certainly much closer to the mic than the other, continuous noise, in fact I think they're very close. The other noise - is it definitely animal? - How long was the noise? - continuous or in short bursts like your sample? - it sounds rather like a motor - could even be something like a compressor, transmitting through the hull of a boat. There seems to be some reverberation there which I assume results from the source-mic distance (and certainly it doesn't sound like very deep water) but it could be be structural reverberation if it actually came from an object with a rigid body such as a boat.I'll be happy if you find out what it is! Regards ppl Dr Peter Lennox Director of Signal Processing and Applications Research Group (SPARG) School of Technology, Faculty of Arts, design and Technology University of Derby, UK p.lennox@xxxxxxxxxxx (01332) 593155 http://sparg.derby.ac.uk/SPARG/Staff_PLX.asp -----Original Message-----From: AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxxxxxxxxx] On Behalf Of Linda SebastianuttoSent: 10 December 2009 14:43 To: AUDITORY@xxxxxxxxxxxxxxx Subject: Unknown biological sound Dear list members, During a nocturnal acoustic survey in shallow waters in the Northern Mediterranean Sea my colleagues recorded some strange sounds of unknown origin. You can find an example in attachment; it is band-pass filtered (50 - 600 Hz), and amplified. Please try to ignore the "clicks" at the end of the sound. Does any of you have an idea of what kind of animal emits a sound like this? Maybe a fish? Thank you in advance L Sebastianutto Linda Sebastianutto, PhD student Cognitive Neuroscience Sector International School of Advanced Studies via Lionello Stock 2/2 Trieste - Italy email: sebast@xxxxxxxx tel: +39 040 3787604 ---------------------------------------------------------------- SISSA Webmail https://webmail.sissa.it/ Powered by Horde http://www.horde.org/The University of Derby has a published policy regarding email and reserves the right to monitor email traffic. If you believe this email was sent to you in error, please notify the sender and delete this email. Please direct any concerns to Infosec@xxxxxxxxxxxThe policy is available here: http://www.derby.ac.uk/LIS/Email-Policy __________ NOD32 4676 (20091210) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com
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