Perception of time-varying signals: timbre and phonetic JND of diphthong

In this paper we propose a linear time-varying model for diphthong synthesis based on linear interpolation of formant frequencies. We, thence, determine the timbre just-noticeable difference (JND) for diphthong /a I/ (as in ‘buy’) with a constant pitch excitation through perception experiment involving four listeners and explore the phonetic JND of the diphthong. Their JND responses are determined using 1-up-3-down procedure. Using the experimental data, we map the timbre JND and phonetic JND onto a 2-D region of percentage change of formant glides. The timbre and phonetic JND contours for constant pitch show that the phonetic JND region encloses timbre JND region and also varies across listeners. The JND is observed to be more sensitive to ending vowel /I/ than starting vowel /a/ in some listeners and dependent on the direction of perturbation of starting and ending vowels.

Engaging in the Crooked Timbre of Humanity: Value Pluralism and Social work

The field of social work ethics is changing. While more established positions, such as utilitarianism and deontology, continue to influence social work thinking and practice, emergent approaches are taking hold, leading to a radical examination of social work as an ethical discipline. To contribute to this unfolding debate, this article examines Isaiah Berlin's notion of value pluralism and its contribution to social work. The argument proceeds by summarising and categorising some of the traditional and emergent theories shaping social work according to metaphors of the ‘head’ (the justice-oriented, rational approaches) and the ‘heart’ (the grounded, particularistic and care-focused approaches). Berlin's value pluralism is then adopted to contend that social work needs to hold both ‘head’ and ‘heart’ ethics in a vital equilibrium to generate the ethics of the ‘hand’ (i.e. the practical response to contested areas of need) and the ‘feet’ (the commitment to change and well-being). These metaphors are then mapped on to a decision-making process and applied to the fraught area of adoption without parental consent

Fast recognition of musical sounds based on timbre

Human listeners seem to have an impressive ability to recognize a wide variety of natural sounds. However, there is surprisingly little quantitative evidence to characterize this fundamental ability. Here the speed and accuracy of musical-sound recognition were measured psychophysically with a rich but acoustically balanced stimulus set. The set comprised recordings of notes from musical instruments and sung vowels. In a first experiment, reaction times were collected for three target categories: voice, percussion, and strings. In a go/no-go task, listeners reacted as quickly as possible to members of a target category while withholding responses to distractors (a diverse set of musical instruments). Results showed near-perfect accuracy and fast reaction times, particularly for voices. In a second experiment, voices were recognized among strings and vice-versa. Again, reaction times to voices were faster. In a third experiment, auditory chimeras were created to retain only spectral or temporal features of the voice. Chimeras were recognized accurately, but not as quickly as natural voices. Altogether, the data suggest rapid and accurate neural mechanisms for musical-sound recognition based on selectivity to complex spectro-temporal signatures of sound sources.

Auditory gist: Recognition of very short sounds from timbre cues

Sounds such as the voice or musical instruments can be recognized on the basis of timbre alone. Here, sound recognition was investigated with severely reduced timbre cues. Short snippets of naturally recorded sounds were extracted from a large corpus. Listeners were asked to report a target category (e.g., sung voices) among other sounds (e.g., musical instruments). All sound categories covered the same pitch range, so the task had to be solved on timbre cues alone. The minimum duration for which performance was above chance was found to be short, on the order of a few milliseconds, with the best performance for voice targets. Performance was independent of pitch and was maintained when stimuli contained less than a full waveform cycle. Recognition was not generally better when the sound snippets were time-aligned with the sound onset compared to when they were extracted with a random starting time. Finally, performance did not depend on feedback or training, suggesting that the cues used by listeners in the artificial gating task were similar to those relevant for longer, more familiar sounds. The results show that timbre cues for sound recognition are available at a variety of time scales, including very short ones.

Répertoire périodique de l'enregistrement : recueil de toutes les décisions administratives et judiciaires sur l'enregistrement et le timbre, comparées avec le droit civil...

1881 (T28).

Répertoire périodique de l'enregistrement : recueil de toutes les décisions administratives et judiciaires sur l'enregistrement et le timbre, comparées avec le droit civil...

1883 (T30).

Répertoire périodique de l'enregistrement : recueil de toutes les décisions administratives et judiciaires sur l'enregistrement et le timbre, comparées avec le droit civil...

1926 (A73).

Répertoire périodique de l'enregistrement : recueil de toutes les décisions administratives et judiciaires sur l'enregistrement et le timbre, comparées avec le droit civil...

1897 (A44).

Répertoire périodique de l'enregistrement : recueil de toutes les décisions administratives et judiciaires sur l'enregistrement et le timbre, comparées avec le droit civil...

1854 (T1).

Répertoire périodique de l'enregistrement : recueil de toutes les décisions administratives et judiciaires sur l'enregistrement et le timbre, comparées avec le droit civil...

1860 (T7).

Répertoire périodique de l'enregistrement : recueil de toutes les décisions administratives et judiciaires sur l'enregistrement et le timbre, comparées avec le droit civil...

1857 (T4).

Répertoire périodique de l'enregistrement : recueil de toutes les décisions administratives et judiciaires sur l'enregistrement et le timbre, comparées avec le droit civil...

1889 (T36).