pitch

Lectures

 

 

Lecture handouts and some video recordings of lectures given to the 2nd year biomedical science course in Audiotory Neuroscience.

 

1) The nature of sound

2) Ear and Brain

Why Missing Fundamental Stimuli are Counterintuitive

The fact that tone complexes with missing fundamentals can be perceived to have a pitch that is below their lowest frequency component can have counterintuitive consequences.

Consider the tone sequence shown in the spectrogram here:

 

 

Music to Deaf Ears - podcast

This podcast by science journalist Dr Carinne Piekema explores how hearing loss affects people, in particular how it affects musicians, and what modern prosthetic devices such as hearing aids or cochlear implants can and cannot do for these patients. It contains insightful interviews with inspirational deaf musicians, some of the UKs leading hearing researchers, as well as simulations designed to show to normal listeners what it would be like to have to rely on a hearing aid or a cochlear implant.

You can listen to the podcast here,

Lecture: Cortical Representations of Complex Sounds

This video clip shows a presentation on the Cortical Representation of Complex Sounds given by Jan Schnupp at a symposium of the British Neuroscience Association meeting in Harrogate on April 18th 2011. 

Periodicity of Sounds and of Envelopes

 

Pitch is determined in most cases by the periodicity of the sound waveform. However, some sounds have other, more subtle periodicities. In some cases, these periodicities may determine the pitch, but in other cases they don't. Here such subtle periodicity is illustrated - the periodicity of the envelope.

Single Formant Vowel with Changing Pitch

 

This sound illustrates one of the sounds used in the study of Cariani and Delgutte (1996) on the coding of pitch in auditory nerve fibers. It is a so-called single-formant vowel, since its spectral envelope has a single peak in frequency (vowels have multiple such 'formants' - see Chapter 4). See Fig. 3-9 in the book.

Here are two consecutive periods, one pair taken from the beginning (green) and one pair from the middle (orange) of the sound:

Non-Periodic Sounds That Evoke Pitch

 

Here are examples of three sounds that evoke pitch without being strictly periodic. A detailed discussion of these sounds can be found in the pitch chapter of the book.

Each of these sounds is approximately periodic, and their spectra have an approximately periodic structure, reminiscent of the strictly harmonic structure of periodic sounds. In each case, there is a clear period. If the sound is shifted by that period, it best resembles its unshifted version.

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