Read and spontaneous speech was produced by 100 male adult speakers of German in a neutral setting and in a Lombard setting, where 80 dB noise was presented over headphones. Average f0 (‘f0mean’) and relative standard deviation of f0 (‘f0varco’) were determined for each speaker in each of the four conditions spontaneous neutral, spontaneous loud, read neutral and read loud. The results confirm that when increasing vocal effort from neutral to loud speech, f0mean increases as well. None of the 100 speakers posed an exception to this effect, but the size of the effect differed between speakers, even after differences in amplitude level were accounted for. F0varco was significantly higher in loud than normal speech for the reading task, whereas in spontaneous speech no significant difference occurred. These results are compared with the literature and discussed with respect to explanations and forensicphonetic implications.

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The visualization of magnetic features can be of forensic relevance in the field of tape authentication. The Research Institute for Material Science and Technology in Zelenograd, Russia, has developed crystals with magneto-optical properties which permit convenient, precise and non-destructive visualization of magnetic information. These crystals change their optical properties according to external magnetic fields. The magneto-optical effects may be used for developing images of the magnetic structure of any analogue or digital recording. In this paper, we first provide some theoretical background about several magneto-optical effects. Subsequently, two experiments on visualization effects that are based on different physical principles (Kerr Effect, Faraday Effect) are described. Selected forensically relevant features detected on analogue recordings are shown. Special emphasis is given to visual features that may be used for authentication purposes.

The process of decoding the content of a message involving Short Message-to-speech conversion is described in the form of a forensic case study. The intelligibility of the message was low, primarily due to the fact that the written input to the text-to-speech system was inTurkish although the system was designed for text-to-speech conversion in German. This created some form of synthesised Turkish with a German “accent”. It is shown how “spectrogram reading” can be employed in the task of deriving phonetic categories from the signal of the synthetic speech message. In order to obtain a maximally accurate estimate of the input typed by the sender, one disputed passage of the SMS-to-speech message was subjected to a simulation. It is described how a full match between the case material and the simulated passage was obtained, despite typographical errors and incorrect Turkish orthography on the part of the sender.

In a lexical decision experiment we investigated whether the mental lexicon is accessed directly by a visual code or by phonological mediation. Subjects were asked to make lexical decisions where phonological coding was either beneficial or detrimental. It was found that subjects used phonological coding when it was helpful and abandoned this strategy when it was a hindrance. These results support the hypothesis that lexical decisions can be based on variable coding operations. The fact that subjects were faster in classifying words when they did not rely on phonological codes is consistent with the assumption of faster visual access to the mental lexicon. Taken as a whole, these results are consistent with models which assume phonological coding to take place after lexical access as well as with models postulating parallel access to the mental lexicon. They are not compatible with models postulating mandatory prelexical phonological coding.