Rhythm
An interactive introduction

Dafydd Gibbon

U Bielefeld

Ak-Phon 2005-07-13

Overview

Definitions and examples of rhythm

Emergent Rhythm Theory (ERT)

Timing factors in linguistics and phonetics

Levels of patterning and isochrony

Phonological rhythm theories

Metrical Phonology, Prosodic Hierarchy

Phonetic rhythm theories

Patterns: Pike, Abercrombie, Jassem

Global isochrony: Isard, Roach, ...

Global pattern ratio: Ramus, ...

Local linear: Low & Grabe

A new strategy

Measuring rhythm types

Inducing hierarchical temporal patterns

Presentation strategy

Lecture: introduction to

basic concepts

approaches

Discussion: intuitive explicanda for “rhythm”

Method practice:

temporal annotation (with annotation software)

selection of units – C/V clusters, syllables, feet

manual analysis of annotation (with spreadsheet)

mean durations

variance & standard deviation of durations

Low & Grabe PVI (pairwise variability index)

Gibbon TPA (temporal periodicity analysis)

Rhythm definitions & examples

Etymology: Middle French & Latin; Middle French rhythme, from Latin rhythmus, from Greek rhythmos, probably from rhein to flow -- more at STREAM

1 a : an ordered recurrent alternation of strong and weak elements in the flow of sound and silence in speech b : a particular example or form of rhythm <iambic rhythm>

2 a : the aspect of music comprising all the elements (as accent, meter, and tempo) that relate to forward movement b : a characteristic rhythmic pattern <rumba rhythm>; also : 1METER 2 c : the group of instruments in a band supplying the rhythm -- called also rhythm section

3 a : movement or fluctuation marked by the regular recurrence or natural flow of related elements b : the repetition in a literary work of phrase, incident, character type, or symbol

4 : a regularly recurrent quantitative change in a variable biological process <a circadian rhythm> -- compare BIORHYTHM

5 : the effect created by the elements in a play, movie, or novel that relate to the temporal development of the action

Rhythm definitions & examples

Rhythm in general...

Rhythms in particular:

Acoustic

Visual

Patterns:

trochaic

iambic

dactylic

anapaestic

Complex:

beat

heterodyne

moiré

What makes rhythm?

Basic position:

rhythm is emergent i.e. a function of many different factors, e.g.

cognitive expectations

“biological clocks”

Temporal properties of prosodic hierarchies - cf. Tillmann's

A prosody: timing level of phonemes

B prosody: timing level of syllables, words

C prosody: timing level of phrases

Articulatory constraints (elastic tissues, weight of bones, ...)

Acoustic patterns

Integrative powers of the ear and hearing

Pragmatic position:

this is all too complicated

let's concentrate first on what we can measure, for heuristic reasons (without rejecting other dimensions)

Emergent complex rhythms (1)

Rhythm 1:

Rhythm 2:

Rhythm 3:

Emergent complex rhythms (2)

Rhythm 1:

Rhythm 2:

Rhythm 3:

Timing factors in speech

Phrase:

Speech tempo

Parenthetic speech

Emphatic accent

Focal / contrastive accent

Phrasal accent (realisation of sentence stress)

Word:

Accent (realisation of word stress)

Word stress

Foot: speech tempo

Syllable: strong/long – weak/short syllables

C & V contrastive phoneme durations

Allophonic duration variation (e.g. Eng. V[+st])

Phonological rhythm theories

Syllable vs. Stress/Foot timing

Pike

Abercrombie

Stratified hierarchies:

Jassem

Prosodic Hierarchies

Selkirk, Hayes

Campbell

General hierarchies:

Metrical Phonology

Phonetic rhythm theories

Global:

variance, standard deviation (isochrony):

Isard

Roach

peak-trough ratio:

Ramus

Periodicity Analysis

Gibbon

Local:

peak-trough alternation ratio:

Low, Grabe & Nolan (PVI)

Gibbon & Gut (RR)

Gibbon (Time Tree Induction)

Dynamic:

Barbosa, Cummins, Wachsmuth, ...

Practical: annotation & analysis

Choose a short speech file

Annotate the following tiers with Praat:

Phonemes

Syllable

Feet

The following can be done automatically, but...

Enter the time-stamps for each tier into separate worksheets of a spreadsheet programm (OpenOffice Calc, Excel)

For each tier:

calculate average length (AL) of units

calculate standard deviation (SD) of units

normalise by dividing SD/AL (0 = isochrony)

Average length and speech rate

AL: Average Length (in msec)

Rate: 1000 / AL (in sec)

SD: Standard Deviation

NDI: an isochrony measure

SD: Standard Deviation

AL: Average Length

NDI=SD/AL: Normalised Deviation Index (>= 0)

Perfect isochrony: NDI = 0

PVI: a binary alternation measure

PVI:

100 * AVERAGE( ABSOLUTE(diffi - diffi+1) / AVERAGE(diffi,diffi+1))

Perspective...

Implementation and further development dynamic approaches:

Barbosa

Cummins

Wachsmuth

Development of rhythm typology measures:

unary (cf. syllable timing)

binary: iambic, trochaic

ternary: dactylic, anapaestic

other ...

Relation of phonetic patterns to patterns of

phonology

morphology

phrasal syntax

discourse

Rhythm (Ak-Phon) - D. Gibbon

2005-07-06T08:34:21