Subject: Re: pitch neurons From: Jean-Sylvain Lienard <jean-sylvain.lienard(at)LIMSI.FR> Date: Mon, 7 Oct 2002 16:30:51 +0200Hello List, From my experience in speech I fully agree with Eli's remark. I would even argue that the very notion of pitch differs according to the abstraction level considered; in my view speech processing implies several levels of abstraction (5 or 6) which correspond to as many steps in time resolution, ranging from some 15 ms to several hundreds of ms at the cognitive level. The F0 measurement that appears at low level is close to a physical property of the signal. It is not defined during the unvoiced segments. However, at higher levels (syllable-size level, word-size level, phrase-size level...) we perceive continuous, smooth pitch properties, loosely related to the low-level F0. We attach different meanings to them: lexical stress, phrase accent, demarcation between linguistic units, interrogation or assertion, speaker's gender, acuteness of the speaker in his/her gender range, emotional state, listener's distance, etc. As Eli points out, the perception of these properties is highly dependent on cognitive and contextual factors. Maybe what we call "pitch" actually refers to a set of different notions that should be defined and processed differently according to their level of abstraction... Israel Nelken wrote: > I would like however to raise another issue: why is >there such a pressure to assume low-level representation (i.e. >subcortical) of pitch? After all, pitch is a pretty high-level >property of sounds, it is invariant to many features of the >physical structure of the sounds, and it is affected by all >kinds of high-level cognitive effects (e.g. capture of >harmonics in streaming conditions). All of these would suggest >to me that whatever is responsible for the pure representation >of pitch (independent of the physical structure of the sounds) >is rather high-level, rather than low-level. > Eli -- Jean-Sylvain Liénard LIMSI-CNRS : BP 133 91403 Orsay Cedex tél 33 1 69 85 81 13 fax 33 1 69 85 80 88 E-mail jean-sylvain.lienard(at)limsi.fr --