Reference Speaker Research Articles

Speaker verification by human listeners over several speech transmission systems

An experiment was performed to find out how well human listeners could determine whether or not two different utterances were spoken by the same speaker. The speech was coded in three ways: high-quality PCM (natural speech), linear prediction encoding (LPC), and ADPCM at 24 kbps. For this experiment all combinations of these three coding methods were used. A group of 16 reference speakers (customers—8 males, 8 females) along with 78 test speakers (16 reference and 62 imposters) were used in the experiment. Two test utterances were used: one for the male speakers and one for the female speakers. The 30 naive listeners who participated in the experiment were required to make same/different judgments. The results will be discussed in terms of the imposter acceptance error rates (miss rates) and customer rejection error rates (false-alarm rates) for the different test conditions.

Speaker's Reference and Semantic Reference

Speaker's Reference and Semantic Reference

Two Dogmas of Linguistic Empiricism

The first person singular is the nucleus on which all the other referential devices depend… The final point of reference, by which a statement is attached to reality, is the speaker's reference to himself, as one thing and one person among others… The world is always open to conceptual re-arrangement. But the re-arrangement is only the addition of new tiers of discrimination to a foundation that remains constant: the recognition of persisting things singled out by active observers who have a statable standpoint as objects among other objects. It is in judgments of perception that the notion of identity, and principles of individuation, are given their earliest sense. That beings, who are capable of action and observation, are born into, and move among, a world of persisting objects is a logical necessity and not a contingent matter of fact. (Stuart Hampshire, Thought and Action, London: Chatto and Windus, 1959, pp. 40, 87).

Listener Performance in a Speaker-Verification Task with Deliberate Impostors

In a previous experiment [Rosenberg, J. Acoust. Soc. Amer. 50, 106(A) (1971)] listener performance was evaluated in a speaker verification task in which 32 “casual” impostors were pitted against eight “true” speakers. A “casual” impostor is one who makes no attempt to mimic the “true” speaker but simply repeats the same test utterance in his own natural voice. In the present experiment four professional mimics were engaged to deliberately imitate each of the eight “true” speakers. After intensive training their recorded utterances were used in an experiment in which 10 listeners participated. Each stimulus presentation was a paired comparison consisting of a challenge and a reference utterance. The reference utterance was one of the “true” speaker utterances while the challenge was, with equal likelihood, a mimic utterance of the reference speaker, a natural utterance of one of the mimics, or another utterance from the reference speaker. The results of the present experiment are compared with the results of the previous experiment cited and the performance of an automatic system for speaker verification [Lummis, J. Acoust. Soc. Amer. 50, 106(A) (1971)].

Strictly for Teachers

The recent publicity awarded the Head Start programme in the United States has done a great deal to shift public attention to preschool education and its problems. Ironically, the effect has been so strong that long established Canadian nursery school and public school programmes have been pushed into the background. This was no more clearly in evidence than at the conference on preschool education held in the fall of 1966 at the Ontario Institute for Studies in Education. The opening speaker's reference to Dr. W. E. Blatz was the only allusion to the Canadian scene. One of the reasons for this rather serious oversight was undoubtedly the fact that while preschool programmes in this country have been in operation for many years, research into the various aspects of the teaching and learning of very young children has been carried out in only a few institutions. The purpose of this article is to describe one such Canadian experiment, its results, and its implications.