Piano touch, timbre, ecological psychology, and cross-modal interference

Richard ParncuttCentre for Systematic Musicology

University of Graz, Austria

ISPS, 28-31 August 2013, ViennaInternational Symposium on Performance Science

AbstractThe piano has a wide timbral range, and performance quality is often judged in timbral terms. Yet despite decades of research, there are still fundamental disagreements about the nature and origin of piano touch. Scientists (acousticians) maintain that the timbre of a single tone cannot be varied independently of its loudness. Performers, humanities scholars and concert audiences take the opposite for granted: timbre and loudness can be independently varied by gestural means. Both sides are right, but their implicit definitions of timbre differ, and both fail to clearly distinguish between physical measures and descriptions of subjective experience. Scientists assume that timbre depends only on physical sound parameters; but experiential parameters generally depend on concurrent input from other senses, the listener’s relevant knowledge and expectations, and immediately preceding and following events. The paradox of timbre disappears if we accept, based on empirical evidence, that timbre generally depends on input from more than one sensory modality (weak synesthesia). Embodied corporality and conceptual metaphors are the norm - not the exception. Gestural and ecological approaches to timbre perception pose existential challenges to disembodied cognitive orientations.

Timbre in traditional psychoacoustics

American Standards Association (1960): “that attribute of sensation in terms of which a listener can judge that two sounds having the same loudness and pitch are dissimilar”

A negative definition!• Neither pitch nor loudness• The multidimensional remainder

Timbre is experience!

• Traditional psychoacoustics: clear distinction between physical and experiential variables

• But many psychoacousticians talk about timbre as if it were physical

• I assume that timbre is always experiential

Timbre depends on

Time domain– temporal envelope

Frequency domain– spectral envelope

Vocal timbre

Time Domain:ArticulationTemporal envelope

Frequency DomainVocal Tract ShapeSpectral Envelope

Timbre of musical instruments

• Mixture of time and frequency domain– Spectral flux: Different temporal envelopes of partials

• Absolute frequency– spectral & temporal envelopes depend on fo

– timbre learned for each absolute frequency

• Spectral interval structure– Clarinet, bowed violin: exactly harmonic– Bell: inharmonic– Piano, guitar: stretched harmonic

Spectral flux in a bass clarinet toneGrey & Moorer (1977)

McAdams (1993)

Timbral spaceSpatial representation of timbral relationships

Method:• Choose some timbres• Rate similarity of all pairs• Multidimensional scaling• Result is usually 3-D, axes:

– onset, centroid, roughess…– depending on tested sounds

Interpretation:• Results difficult to generalise• Cognitive representation?• Distances in space depend on

exposure & familiarity McAdams et al. (1995), Psychological Research

Ecological psychology of timbre• Environmental interaction• Experience as byproduct of interaction

(epiphenomenon)

Theory of James J. Gibson:• Affordances and information pick-up• Invariances of sound sources• Perceptual learning

Complementary to the cognitive approach Relationship to evolutionary psychology

Distal versus proximal stimuliExternal versus internal focus of attention

In sport and music, performance may be better if attention directed to effects of movements - not movements themselves (Wulf & Prinz, 2001): • Golf: attention on goal, not movements• Pianists: attention to sound, not technique

Why?• Sophisticated unconscious motor control mechanisms • Perception of goal inseparable from proprioception

ImplicationPerception of timbre involves source perception

Ecological-evolutionary foundationsof auditory perception

Assumption: Sounds are only interesting ( consciously perceived) if they carry information about environmental interaction that could affect survival or reproduction.

The affordances of a sound source • what it means to us • what we can do with it

Timbre reflects affordances!• Human voice• Lion footsteps, waterfall, car, gun…

OPEN

BRIGHT

CLASSICALAIRY

VIBRATO

SPOKEN

SMOKEY

HARSH

PRESSED

CLEAR

NATURAL

BREATHY

LOOSE

NASAL

FORCEFUL

FIXED

pleasant

soft

dark

relaxed

yawning

held back

resonanteasy

round

black

swinging

support

forward

(Prem & Parncutt, 2007)

Words to describe the jazz voice

“I fell in love with his voice. He is African American, and his voice has this depth, it is souly, in a wonderful way. He is like a gentleman, and has this warmth. He gives his voice space and that arouses a very balanced feeling in me. His sadness, his elegance, his joyfulness really come through, so that I can experience them.”

Affordances of vocal timbre

Data collected by Ella Prem

Timbre is multimodal

• Performer can’t separate timbre (as experience!) from gestures used to achieve it

• Listeners share the performer’s experience (empathy)

How?• audiovisual mirror neurons (Kohler et al., 2002) • auditory-motor interactions (Zatorre et al., 2007)

ProprioceptionPerception of position and movement of body

parts and associated muscular tension

Part of the somatic sensetouch, proprioception, temperature, pain

An aspect of corporalityAspects of music experience that depend on the bodies

of performers and listeners

Weak synesthesiacross-modal interference

• All perceptual modalities: seeing, hearing tasting…• The norm - not the exception• Ecologically natural - cognitively strange

The limits of subjective analysisWe cannot completely separate…• input from different modalities: hearing, vision, touch• sensations within a modality (pitch, timbre).

A non-musical example

When you taste yoghurt with a lighter (table-) spoon, it seems• thicker • sweeter• more expensive

Harrar & Spence (2013). The taste of cutlery. Flavour, 2: 21.

Weak synaesthesia in music

• Musical pitch “rises” and “falls”• A piece “moves”• A voice is “warm”, “round”, “relaxed”

Embodied cognitionin different disciplines

• Psychology: cognition depends on features of the physical body of an agent (Wilson & Foglia, 2011)

• Music psychology: dance, rhythm, aesthetics etc. (Leman, 2008).

• Humanities: conceptual metaphor, ideas in one domain help us understood in another (Lakoff & Johnson, 1980).

Timbral range of the piano

One note: • Louder is brighter

Many notes:• higher is brighter• physical interactions among strings,

soundboard, internal resonances• dependence on timing, dynamics, pedaling

The pianist’s “touch”A traditional psychoacoustic approach

Physics:• Hammer hits string in free flight• Only free parameter is hammer velocity (shank rotation?)• Fingertips hit the keys differently in legato and staccato touch

Perception:• Any effect beyond hammer-velocity effect is usually inaudible

due to masking(cf. “touch precursor”, “early noise”; Goebl et al., 2004)

Piano touch: A synaesthetic approach

For the pianist:• All aspects of somatic sense: touch, position, movement,

temperature, pain…

For the audience:• Vision (perception of gesture)• Projected somatic sense (empathize with performer)

For both:Multisensory perception of the interaction between the instrument and the performer

The feel of a piano

“Pianos and rooms are generally interdependent: anyone who has ever travelled with a piano knows that the same Steinway or Bösendorfer not only sounds different in different halls, but also seems to react differently in its mechanism. Indeed, the resistance of the key, over and above the measurable mechanical aspect, is a psychological factor”

Alfred Brendel (1976)

The feel of a piano

For pianists, the physical resistance or bounciness of the piano mechanism depends• physically on temperature and humidity• psychologically on touch-sound relationship

(to which they are very sensitive)

Multisensory piano timbreIn physics, spectral and temporal envelopes of an isolated piano tone cannot be changed independent of intensity

In psychology and experience, timbre involves interactions between:• performers’ proximal sensations (tactile, auditory, visual,

proprioceptive) • distal perception and cognition (performance space;

communication with the audience; cultural context)

These statements are not contradictory!

Weak synasthesia in wind/string timbre

• independent control over pitch and timbre, but:

• intonation and timbre not psychologically separate (Ely, 1992; Geringer & Madsen, 1981; Platt & Racine, 1985)– musicians who play with good timbre are judged

by experts and amateurs to have good intonation and vice-versa

Weak synesthesia in Renaissance choral timbre

Listeners, audiences want “authentic” timbre.Some confuse that with just intonation.

The sound is presumably optimal near 12-tone equal temperament (Devaney et al, 2011)

Weak synaesthesia in acousmatic music

Acousmatic music is abstract, electronically synthesized sound from loudspeakers.Ecological approach to aesthetics: • Listeners constantly guess and imagine

sources or causes of musical sounds – as in everyday life

• Electronically generated sounds sound more “musical” if similar to familiar sounds

Disembodiment of music theory and cognitive music psychology

• Music theory depends on the score• Cognitive music psychology depends on

abstract cognitive structures

The ecological solution:Study our experience of our physical interactions! Example: complex tones in speech and music (Terhardt, 1984).

A new definition of timbre

1. Experiential2. Holistic and multimodal3. Quantitative and qualitative4. Proximal and distal

1. Timbre is experiential

• Like pitch, loudness, and (in vision) color• Not a physical parameter!• Corresponds to physical states and events

2. Timbre is holistic and multimodal

Timbre depends generally and intrinsically on• input from all senses: hearing, vision, touch, gesture• physical context: acoustics and appearance of listening space• temporal context – immediate, global• empathy: shared or projected knowledge, experience,

expectations• emotional reactions• associations

Our ability to separate these components is limited.

3. Timbre is qualitative and quantitative

• complete description: both kinds of data• both are intrinsically vague and intangible • quantitative approach:

– multidimensional (axis labels are qualitative)• qualitative descriptors

– refer to environment, body, speech (Traube, 2004)

4. Timbre is distal and proximal

• A complete description includes both• Traditional psychoacoustic approach is proximal• Combine with ecological source-based approach

Why? Timbre generally depends on imagined visual and tactile properties of sound sources, and past experience of those sourcese.g. different clarinet registers are all “clarinet”

Solving the “touch” problem

• Redefine timbre: combine experiential psychophysics with ecological psychology

• Promote interdisciplinary interaction: humanities, sciences and performance

• Abandon philosophical materialism: (artistic) experience exists!