Into the time domain

20120206_010_moon_1200

Orthopteran community after nightfall (t/f-8)


 

time & pitch transformation

Birds are thought to have a finer temporal discrimination of sounds than humans. This means they hear the individual elements of composite sounds that for us appear as a single blurred sound. Their hearing may have up to eight times the temporal resolution that ours can achieve.

One way getting some impression of this is by slowing down bird sounds; the simple way of doing this also lowers the pitch of the sound by the same factor and this is a fascinating way of tuning in to the hidden depth of birdsong, a kind of transformation to a more human musical sensibility.


nightingale dawn

Nightingale in dawn chorus – Valencia, Spain:


Slowed by a factor of 4. Gorgeous, eh?


skylark

7 second extract of song (with another skylark in the distance):


Slowed by a factor of 3:


Slowed by a factor of 6:


The final phrase (lasting c. 1 second):


Slowed by a factor of 12:


[Tech note: these were analogue transfers from Canary and, although they have more high frequency content, most of it appears to be aliasing.]

A longer section of the same bird:


Slowed by a factor of 8:


buntings – Emberizidae

The bunting family are generally considered to have simple songs: individual males have a repertoire of one or a few types of song that are stereotyped – that is, the songs have a rigid form and each repetition is virtually identical, though particular instances may leave out some of the ending notes. The apparent simplicity is relative to our hearing and a subtly efficient complexity revealed when we expand the time frame.

Yellowhammer Emberiza citrinella

Two song-types from the same male, recorded in Strathspey, Scotland:


Slowed by a factor of 4:


Slowed by a factor of 8:


Slowed by a factor of 16:

Reed Bunting Emberiza schoeniclus

A single song recorded on the Moray moors, Scotland:


Slowed by a factor of 4:


Slowed by a factor of 8:


Slowed by a factor of 16:

Corn Bunting Miliaria calandra

Single song recorded in Oxfordshire, England:


Slowed by a factor of 4:


Slowed by a factor of 8:


Slowed by a factor of 16:

Black-headed Bunting Emberiza melanocephala

Single song recorded in Lesvos, Greece:


Slowed by a factor of 4:


Slowed by a factor of 8:


Slowed by a factor of 16: