Category Archives: Acoustics

Raspberry Pi First Run

I checked the UPS tracking number periodically today. My Raspberry Pi was marked as delivered at about 2:30 today. When I got home, I found the package. I still needed to prepare the SD card, so I brought up the RasPi Wiki instructions for SD card setup and went with the Debian Squeeze distribution to… Read More »

Personal Research and the Budget

Diane and I are working on a personal project to put together an acoustic sampling system that could yield information about the activity levels of snapping shrimp. Whitlow Au and his group have done this sort of thing out in the Pacific. Of course, they’ve gotten research funding to do it. We’re looking to do… Read More »

Python and the STFT

I’ve been going through biosonar data and while the SciPy specgram method is serviceable, I was interested in a short-time Fourier transform (STFT) implementation. There are a couple of ad hoc routines on Stack Overflow and the like, but I’ve started off with the Google Code PyTFD module. There are others out there as well,… Read More »

Some Data Analysis and Visualization

As noted here before, I’m working through refreshing archived data, mostly from CD-ROM media. I’ve run into a whole batch of CD-ROM disks that are in good physical condition, but which mostly cannot be read. I’m trying some tools that I’ve seen recommended, but would be open to suggestions. But the whole point of getting… Read More »

The Weekend

I don’t know what other people got up to this weekend, but mine has been pretty well filled with computing projects. I’ve been working with my friend Marc to try to get to the bottom of the Verizon FIOS connection foul-up. We each ran TCPDUMP on our respective machines while making a request that could… Read More »

Cool Acoustics Product: Tern Micro GR4

I occasionally check out the Tern Micro website. They are manufacturers of controllers and expansion boards for embedded applications. Their controller boards use IAPx86 class CPUs and are programmed in C. A few years ago, I had checked with them about whether they had components suitable for a field acoustic recorder, and given the short… Read More »

Plotting a Dolphin Biosonar Click Train

I’ve been busy recently doing up figures for a paper on dolphin biosonar. One of the figures we ended up turning in earlier this week wasn’t exactly as I wanted it, but deadlines don’t wait. I put a lot of hours into trying to find alternative plotting for it, but just hadn’t found the right… Read More »

Listening to Snapping Shrimp

I’m working on setting up a citizen scientist project to document where snapping shrimp (family Alpheidae) are active pre- and post-contamination by the oil spill in the Gulf of Mexico. In this post, I just want to introduce the basic concepts and provide an example sound file. Snapping shrimp comprise a number of species, mostly… Read More »

Acoustics Blooper in NCIS

I saw the NCIS episode “One Shot, One Kill” and noticed a blooper in the show. Maybe that’s not that cool, but this particular blooper requires knowing something about acoustic localization. This is the technology that is being used to let marine mammal researchers place the position of whales who are vocalizing and also lets… Read More »

Sirenian International Goes Sociable

Sirenian International, a manatee conservation and public outreach organization, now has a Facebook group. SI also has a field course in Belize that one can sign up for: Ecology, Behavior & Conservation of Manatees & Dolphins A Unique Field Course in the Drowned Cayes, Belize Host: Caryn Self-Sullivan Type: Education – Class Network: Global Start… Read More »

Biosonar Turns Waspish

Nature (7228, p.361) had notice of an article in Biological Journal of the Linnean Society (96, 82-102, 2009) that demonstrates the use of biosonar in several species of parasitic wasps. These wasps seek out beetle larvae in trees, using hammer-like ends of the antennae to produce sound. So far as I know, this is the… Read More »

A Study on Whistles — And Only Whistles

There’s a study in the Journal of Comparative Psychology that comes somewhat up my alley. Quick, Nicola J. and Vincent M. Janik. 2008. Whistle Rates of Wild Bottlenose Dolphins (Tursiops truncatus): Influences of Group Size and Behavior. J. Comp. Psych. 122(3):305-311. OK, so what are the authors reporting as results? A lot of that is… Read More »

Blast from the Past: IC and Impedance Matching

Today, Nelson Alonso turned up on AtBC and turned in an amazing performance that has to be seen to be believed. Alonso is a long-time second-tier “intelligent design” creationism cheerleader; I’ve had experience in online discussions with him since the late 1990s. Some of his braggadocio touched upon having a long history of online discussion.… Read More »

Sigh… Another Item for the Wish List

M-Audio has updated its handheld Microtrack solid-state recorder to the Microtrack II. The specs are attractive. It records in stereo to Compact Flash or MicroDisk format cards, in either WAV or MP3 formats. It can record at up to 96 kilosamples/second at 24 bits per sample. It has both 1/4″ and 1/8″ microphone/line inputs, and… Read More »