Speech register influences listeners' word expectations.

We utilized the N400 effect to investigate the influence of speech register on predictive language processing. Participants listened to long stretches (4 - 15 min) of naturalistic speech from different registers (dialogues, news broadcasts, and read-aloud books), totalling approximately 50,000 words, while the EEG signal was recorded. We estimated the surprisal of words in the speech materials with the aid of a statistical language model in such a manner that it reflected different predictive processing strategies; generic, register-specific, or recency-based. The N400 amplitude was best predicted with register-specific word surprisal, indicating that the statistics of the wider context (i.e., register) influences predictive language processing. Furthermore, adaptation to speech register cannot merely be explained by recency effects; instead, listeners adapt their word anticipations to the presented speech register.

Evaluation of various sets of acoustic cues for the perception of prevocalic stop consonants. I. Perception experiment.

The purpose of the study presented in this paper and the accompanying paper [Smits et al., J. Acoust. Soc. Am. 100, 3865-3881 (1996)] is to evaluate whether detailed or gross time-frequency structures are more relevant for the perception of place of articulation of prevocalic stop consonants. To this end, first a perception experiment is carried out with "burst-spliced" stop-vowel utterances, containing the Dutch stops /b,d,p,t/ and /k/. From the utterances burst-only, burstless, and cross-spliced stimuli were created and presented to listeners. The results of the experiment show that the relative importance of burst and transitions for the perception of place of articulation to a great extent depends on place and voicing of the stop consonant and on the vowel context. Velar bursts are generally more effective in cueing place of articulation than other bursts. There is no significant difference in the effectiveness of /p/, /t/, and /k/ transitions, while /b/ transitions are more effective than /d/ transitions. The release burst dominates the perception of place of articulation in front-vowel contexts, while the formant transitions are generally dominant in nonfront vowel contexts. The bursts of unvoiced stops are perceptually more important than the bursts of voiced stops.

Evaluation of various sets of acoustic cues for the perception of prevocalic stop consonants. II. Modeling and evaluation.

The purpose of the study presented in this paper and the accompanying paper [Smits et al., J. Acoust. Soc. Am. 100, 3852-3864 (1996)] is to evaluate whether detailed or gross time-frequency structures are more relevant for the perception of prevocalic stop consonants. To this end, first a perception experiment was carried out with "burst-spliced" stop-vowel utterances. This experiment is described in the accompanying paper. The present paper describes the second part of the investigation, i.e., the simulation of the behavior of the listeners in the perception experiment. First, a number of detailed and gross cues are measured on the stimuli. Next, these cues are mapped onto the observed perceptual data using a formal model of human classification behavior. The results show that in all cases the detailed cues, such as formant transitions, give a better account of the perceptual data than the gross cues, such as the global spectral tilt and its initial change. The best-performing models are interpreted in terms of the acoustic boundaries which are associated with the perceived linguistic contrast. These boundaries are highly interpretable linear functions of five or six acoustic cues, which give a quantitative description of the often-discussed "trade-off" relation between the various cues for perception of place of articulation in stop consonants.