Special issue regarding “Methods for marine mammal passive acoustics” on JASA

Just like my recent publication in JASA, there is a special issue on JASA focus on passive acoustic monitoring of marine mammals. You can find the content list in the following link:

Methods for marine mammal passive acoustics

Passive acoustic monitoring of marine mammals is indeed a still growing field in both ecology and acoustics. Due to the difficulty of marine mammal monitoring, there are more techniques are developed to assist people understand the underwater life. And I believe this is the current trend of ecological monitoring no matter in underwater or terrestrial animals. By using autonomous devices to collect data in long duration or using automatic method to facilitate the analysis on large sample size, more quantitatively results with less subjective determination can be obtained.

Advertisements

New article online: An automatic detection algorithm for extracting the representative frequency of cetacean tonal sounds

Here is the newest online article regarding automatic detection of cetacean vocalizations:

 

An automatic detection algorithm for extracting the representative frequency of cetacean tonal sounds

J. Acoust. Soc. Am. Volume 134, Issue 3, pp. 2477-2485 (2013); (9 pages)

Tzu-Hao Lin1, Lien-Siang Chou1, Tomonari Akamatsu2, Hsiang-Chih Chan3, and Chi-Fang Chen4

1Institute of Ecology and Evolutionary Biology, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan 
2National Research Institute of Fisheries Engineering, Fisheries Research Agency, 7620-7 Hasaki, Kamisu, Ibaraki 314-0408, Japan 
3Ship and Ocean Industries R&D Center, 14F, Number 27, Section 2, Zhongzheng East Road, New Taipei City 251, Taiwan 
4Department of Engineering Science and Ocean Engineering, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan 

 

Most studies on tonal sounds extract contour parameters from fundamental frequencies. The presence of harmonics and the frequency distribution of multiple tonal sounds have not been well researched. To investigate the occurrence and frequency modulation of cetacean tonal sounds, the procedure of detecting the instantaneous frequency bandwidth of tonal spectral peaks was integrated within the local-max detector to extract adopted frequencies. The adopted frequencies, considered the representative frequencies of tonal sounds, are used to find the presence of harmonics and overlapping tonal sounds. The utility and detection performance are demonstrated on acoustic recordings of five species from two databases. The recordings of humpback dolphins showed a 75% detection rate with a 5% false detection rate, and recordings from the MobySound archive showed an 85% detection rate with a 5% false detection rate. These detections were achieved in signal-to-noise ratios of −12 to 21 dB. The parameters that measured the distribution of adopted frequency, as well as the prominence of harmonics and overlaps, indicate that the modulation of tonal sounds varied among different species and behaviors. This algorithm can be applied to studies on cetacean communication signals and long-term passive acoustic monitoring.

 

Please contact me if you are interested in this article. Also feel free to discuss here!

2013 symposium regarding marine mammal acoustics

For people interested in marine mammal acoustics:

This year, there are two symposium/workshop regarding marine mammal acoustics. One workshop is “cetacean echolocation and outer space neutrinos: ethology and physics for an interdisciplinary approach to underwater bioacoustics and astrophysical particles detection” held in Erice, Sicily. The other one is “20th biennial conference on the biology of marine mammals” held in Dunedin, New Zealand.

 

ERICE international workshop

20th Biennial conference on the biology of marine mammals

 

I’ll attend both symposiums and have oral presentations! Please feel free to contact me if you also attend these two meetings.

[TED] Bernie Krause: The voice of the natural world

Here is an excellent talk regarding the soundscape or acoustic ecology research on TED.

The signature of soundscape can be divided by “geophony, biophony, and anthrophony” three kinds of components. Through the soundscape analysis, we can receive more information from the recording environment which may not revealed by our eyes. An good example of application is presented in this talk: the difference of acoustic environment before and after artificial interference. Such kind of acoustical analysis can play a key role in this kind of environmental research in the future, but people still need to find a better way to make audiences more easily to perceive the sound sources of acoustic recordings.