Category:Information in Communication Sounds

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The sounds that animals use to communicate at a distance, to declare their territories and attract mates, are typically pulse-resonance sounds (Patterson et al., 2008). These sounds are ubiquitous in the natural world and in the human environment. They are the basis of the calls produced by most vertebrates (mammals, birds, reptiles, frogs and fish); they are also the basis of many invertebrate communication sounds, such as those of the crustaceans (e.g., popping shrimp) and insects (e.g., grasshoppers and cicadas). Although the structures used to produce pulse-resonance sounds can be quite elaborate, the mechanism is conceptually very simple. The animal develops some means of producing an abrupt pulse of mechanical energy which causes structures in the body to resonate. From the signal processing perspective, the pulse marks the start of the communication and the resonance provides distinctive information about the shape and structure of the sounders in the sender’s body, and thus, distinctive information about the species producing the sound.

In the majority of animals that communicate by sound, nature has adapted existing body parts to create the structures that produce the communication sounds. In humans, as in almost all mammals, the vocal apparatus is based on the tubes that carry food and air from the entrance of the mouth and the entrance of the nose to the stomach and lungs, respectively. As the animal grows, these tubes have to get longer to keep the nose and mouth connected to the lungs and stomach. As the tubes get longer, the resonances in the vocal tract ring more slowly. This is a general physical principle of sound production; as things get larger or more massive, they vibrate more slowly. Similarly, as the vocal tract gets wider, the vocal cords get longer and more massive, which means that the glottal pulse rate decreases as the animal grows. The sound producing mechanism typically maintains its overall shape and structure as the individual grows. As a result, the set of messages that a species uses to communicate remain more or less the same as the animal grows, but the message is carried by sounds that vary in their resonance rate and their pulse rate. This category of the wiki, Information in Communication Sounds, focuses on the distinction between the message of a communication sound and the size information in the sound that carries the message from the sender to the listener. The main concepts are described, with reference to speech sounds, animal calls and musical tones, in The Size Information in Communication Sounds.

When we refer to the size information in communication sounds, we are referring to the physical size of the components of the physical system that produces the sound. Once the sound is in the air, free from the source, the proper name for the information in the sound that changes with the size of the source is acoustic scale, that is the scale of the acoustic components of the sound (Cohen, 1993). Communication sounds are typically generated by source/filter systems (Fant, 1970); in this case, the word "source" refers to the mechanism that produces the pulses that excite the system, and the word "filter" refers to the set of resonators that respond to this pulsive excitation. Communication sounds contain two forms of acoustic scale information associated with (a) the size of the components that produce the stream of pulses and (b) the size of the resonators that filter the excitation pulses (Irino and Patterson, 2002). For humans, the most familiar communication sound is speech and the relevant components of the speech production system are (a) the vocal folds (the source) and (b) the cavities of the vocal tract (the filter). A brief introduction to the acoustic scale information in speech sounds is provided in Acoustic Scale in the Waves and Spectra of Communication Sounds.


Roy Patterson


Contents

The size/scale information in speech sounds

A simple, formant-pattern model of speech communication

An overview of vowel communication: Top panel: the role of the resonators in producing the sound. Middle panel: the wavelengths transmitted from the speaker to the listener. Bottom panel: the decoding of the vowel in the perceptual system of the listener.

The Role of Vocal-Tract Length in Speech Communication

The role of size in speech sounds

The role of GPR and VTL in the definition of speaker identity

Gaudrain, Li, Ban, Patterson, Interspeech 2009

Estimating the size and sex of a speaker from their speech sounds Ambox warning pn.svg Access to this page is currently restricted

Figure 1. Mechanisms involved in estimating speaker size. Bottom panel: Dual profile of a vowel showing the formant wavelengths and the pitch wavelength. Middle panel: Conversion of formant wavelengths to vowel type and acoustic scale of the vocal-tract filter. Top panel: conversion of acoustic scale values to a common code for height estimatation.

A statistical, formant-pattern model for estimating vocal-tract length from formant frequency data

Figure 13: Predicting the population distribution over the GPR-VTL plane and the path of an average male and female through it as they develop.

The Size Information in Communication Sounds

The size information in speech sounds

The size/scale information in musical tones

The perception of family and register in musical tones

Sixteen common instruments illustrating four registers within each of four instrument families

The effect of phase in the perception of octave height Ambox warning pn.svg Access to this page is currently restricted

Attenuating the odd harmonics of complex tone shifts the pitch vertically up the pitch helix

The robustness of communication to changes in acoustic scale

The robustness of bio-acoustic communication and the role of normalization

Scale-shift covariant auditory images


The scale-shift covariant Auditory Image (sscAI) Ambox warning pn.svg Access to this page is currently restricted

The sscAI

Published papers for the Category: Information in Communication Sounds

Size information in speech sounds: Patterson et al. (2008), Turner et al. (2009)

Size information in musical sounds: van Dinther and Patterson (2006)

References

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