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IN OUR INFORMATION AGE, Robert Logan and Louis Lenzi assert it is the orchestration of a comprehensive consumer experience—rather than the creation of an object—that should dominate the genesis of a product. Using the development of an interactive-TV system as an example, they refer to their process as “mindesign,” a multidisciplinary perspective on product design that defines engaging experiences, eliminates the fear of complexity, and encourages exploration and discovery.

CREATIVE DESIGN METHODOLOGIES work best in the hands of creative design organizations. In the complex and bewildering world of digital technology and entertainment, Robert Logan has put together a team of humanists, artists, technologists, and capitalists to define strategic visions for his company and to develop successive generations of innovative, consumerdriven products. In this organizational model, design and strategy are managed as different aspects of the same creative process.

Traditionally, research at Thomson has been conducted in the laboratory. This study, however, took place in users' homes. This work investigated the television (TV) viewing behaviors of nine households over an 10-week period and was designed to provide a better understanding of how and why people watch TV within the home. Applying a combination of methods from the fields of human factors and anthropology, viewing behaviors were observed via computer-logged TV commands, interviews, questionnaires, photographs, and other methods. Analysis of the resulting data will cover three major areas: 1) tabulation of computer-logged TV usage behaviors, 2) tabulation and interpretation of personal observations, and 3) comparison of the computer-logged data with the personal observations. This analysis will result in a more complete list of user requirements that includes both behavioral and emotional usability issues. Such requirements will be applied to the design of future consumer electronics.

Telephone handset design has evolved for decades along with advancements in technology and manufacturing methods. Today, a handset could be reduced to a slim rod incorporating a miniaturized earpiece and microphone. However, most handsets look like the venerable K-type handset, such as those found today on many household and business telephones. Should future handsets continue to follow suit, or are there significant opportunities for improvement? Initially, we conducted five focus groups to answer this question. To begin each session, we photographed consumers holding handsets to assess gripping styles. Then, consumers rank ordered six conventionally designed handsets and six progressively designed handsets according to several ergonomic and emotional attributes. They also critiqued the handset designs according to personal preference and built clay models of their ideal handset. Based on this input, our team of human factors and industrial design specialists designed 6 new concepts, then obtained quantitative and qualitative feedback by conducting thirty focus groups in three metropolitan areas. This follow-on research, that included free association, sample handset assessment and, paired comparison and ranking exercises, identified significant opportunities to improve handset comfort, appearance, and emotional appeal. A Kruskall-Wallace H-test showed few significant differences in consumer preferences among 18 sample handsets. Our results indicate that users prefer a handset that can be shouldered, looks modern, feels good in the hand, and conforms to the face. We found that users are receptive to design innovation, but only if there is an ergonomic payoff. We include a discussion of detailed design recommendations in the last two sections.

Remote controls are part of everyday life. Unfortunately, the experience of using a remote is not always pleasurable. This research documents the process of developing multiple remote control concepts that are ergonomic and enjoyable to use. As part of the design process, we researched design concepts with 147 consumers in three cities. The research yielded design-specific data, but also provided insight to some general consumer trends in remote usage and preference for children and adults. This research also suggests that an expanded definition of usability may be required for certain product categories such as consumer electronics. Central to this expanded definition are the concepts of behavioral and emotional usability. Behavioral usability refers to the traditional work related definition of usability. Emotional usability refers to additional needs, such as entertainment or enjoyment, that enhance the product usage experience.

The current study investigated the ability of subjects to perceive source characteristics (the gender of a human walker) of a naturally occurring auditory event (human walking). A number of acoustic properties were measured and subjected to statistical analyses in order to identify those properties that differentiate male and female walking footsteps. A principal component analysis on the statistical properties of the spectral energy distributions then identified two classes of information that were important in determining subject perception of the gender of a walker: (1) the spectral peak which integrates the information about the spectral central tendency of frequency and shape of the spectral peak; and (2) the contribution of high-frequency spectral components. A follow-up experiment then manipulated these spectral properties to verify their contributions in the perceptual classification of walker gender. Additionally, the effect of shoe on the gender judgement in walking sequences was assessed by having both male and female walkers wear male's shoes.

The current study continued the previous research using as stimuli the sounds of humans walking on a hard surface [Li et al., J. Acoust. Soc. Am. Suppl. 1 87, S24 (1990)] to investigate the acoustic properties that delineated categories of ecologically valid auditory source events. Various statistics of the walking spectra were computed, and subjected to a factor analysis in order to identify the spectral properties that differentiated between actual gender class of source events (male and female walkers). Two classes of information were identified as important in distinguishing between the male and female spectra: (1) central tendency and (2) slopes of spectral attack and decay. A multiple regression analysis indicated the importance of these classes of information in determining the perception of the walker gender. A follow‐up experiment then manipulated these statistical properties to verify their contributions in the perceptual classification of walker gender. [Work supported by NSF.]

The act of walking across a hard surface by humans imposes a nonarbitrary structure on an acoustic waveform. This research investigated the sensitivity of listeners to this structure and evaluated the ability of listeners to extract certain information about the source of the sound. Three experiments were conducted. In experiment 1, stimuli produced by eight walkers (four male and four female) were presented to listeners in an AX (same/different) walker discrimination task. Experiment 2 evaluated listeners' ability to label the walkers by gender. Finally, experiment 3 assessed the ability to identify the individual walkers. The results suggested that the listeners could discriminate between the walkers and that listeners can recover some of the physical characteristics of the source based on the auditory signal.

This research assessed the nature of acoustic information used in talker normalization and speaker recognition, evaluated three models of talker normalization, and investigated the relationship between the mechanism(s) used by talker normalization and speaker recognition. Two experiments were conducted. Experiment 1 was an AX (same/different) verification task designed to assess the ability of listeners to discriminate eight talkers in three stimulus conditions. The results suggested that listeners are consistent in their confusions across stimulus conditions and can use relatively steady‐state acoustic information to discriminate the talkers. The confusion matrices from experiment 1 were used to create three talker normalization conditions in experiment 2: single talker, confusable talkers, and discriminable talkers. Listeners in experiment 2 were tested in an AX (same/different) phoneme discrimination task. The results suggest that relatively dynamic information is important for talker normalization and that the contextual tuning model is the most appropriate conceptualization of the talker normalization process. The results are discussed with respect to the relationship between talker normalization and speaker verification.

Temporal order of onset identification boundaries and difference thresholds (DLs) were measured for stimuli modeled after two formant speech stimuli that varied in voice onset time (VOT). The stimuli had dynamic onset transitions and consisted of a tone pair that varied in onset relative to a noise whose center frequency matched the higher frequency tone. DLs were measured relative to 0- and 7-msec onset delays (as well as 49- and 56-msec onset delays) by using a method of constant stimuli with a two-interval temporal forced choice psychophysical procedure. Discrete thresholds were found for noise lead conditions, but tone lead conditions were very difficult for most subjects. With rising-onset stimuli, evidence was found for long DLs based upon a fixed threshold location at 32–38 msec, and thus independent of the standard stimulus. With falling-onset stimuli, the short (5- to 20-msec) DLs were roughly proportional to the standard (0- or 7-msec) onset difference, although there was evidence for an additional fixed perceptual boundary at a longer (30- to 40-msec) onset difference. A noise burst at stimulus onset seemed to act as a type of masking stimulus, causing a shift in temporal order threshold to longer onset differences. The 30- to 40-msec fixed threshold location is similar in magnitude to those typical of VOT voicing boundaries for stop consonants of English.

Recent research has convinced us that limitations on temporal order judgments (TOJ) do not provide an adequate acoustic basis for voicing contrast. Our correct research focuses on F1 cutback, a second major cue in voicing contrasts. F1 cutback exhibits categorical perception and at least some of the parameter dependencies found for voicing contrasts, but not found with TOJ. These results will be described. The possibility that F1 cutback, acting alone or in conjunction with temporal order cues, may serve as a major acoustic cue for contrasts will be discussed.

Feustel et al. [J. Acoust. Soc. Am. Suppl. 1 83, S55 (1988)] evaluated performance of humans in a speaker identity verification (SIV) task with the intent of improving the performance of a LPC‐cepstral based verification algorithm. This study uses the general methodology and signal processing techniques developed by Feustel et al. to further investigate the nature of potential invariant acoustic information (within a speaker) used by humans to verify a speaker's identity. Subjects were presented natural speech or modified natural speech stimuli drawn from a corpus of spectrally distinguishable and spectrally ambiguous utterances. The results suggest that humans can use information from both the glottal (source) waveform and spectral envelope. Overall, the glottal waveform provides more reliable information. The results will be discussed in this context.

Our previous research described at the last Acoustical Society Meeting [Pastore et al., J. Acoust. Soc. Am. Suppl. 1 77, S27 (1985)] investigated duration effects in the perception of tone analogs to the delayed F1 onset cue for voicelessness. Two groups of psychophysically experienced subjects exhibited statistically significant dependencies on stimulus duration, with longer stimuli resulting in shorter delayed onset boundaries. This pattern of results is opposite to those reported for voicing contrast boundaries as a function of target stimulus duration. The second group of subjects now has replicated this statistically significant reversed duration dependency for equivalent stimuli with added harmonic structure. Naive subjects with the identical task and stimuli exhibit a statistically significant dependency on duration consistent with published findings for synthetic speech, and thus opposite to that found for our experienced subjects. The results are discussed in terms of the role of perceptual learning in the perception of voicing cues. [Research supported, in part, by National Science Foundation grant 8302873.]

The McGurk effect recently has been variously conjectured to be based upon a precategorical interaction or integration of information from the auditory and visual representation of the linguistic event. The conjecture of precategorical interactions, which rejects the original notion of post‐categorical interactions, may be in the form of a specialized module for speech or language, or may contribute to a logic‐decision process, either of which leads to a relatively discrete perception of speech. While not disputing such precategorical interactions for language, the research to be described demonstrates post‐categorical interaction of auditory and visual representations of phonemes. The stimuli are nonword CVC syllables. The set of auditory stimuli is edited from natural speech, while the set of visual stimuli includes the orthographic representations of the auditory stimuli syllables. Evidence for interactions in identification of initial phonemes is based upon both error rates and reaction times. [Research supported in part by an NSF grant to the first author.]

Several years ago, we discovered that the perception of an initial voiceless consonant “p” in a monaural CV syllable could be altered by a burst of noise roughly coincident (+/−50 ms) with the onset of the stop. These noise‐induced misperceptions were found only when the noise was contralateral to the consonant and approximately equal in intensity (+/−20 dB). We later found that the effect was highly dependent upon the subsequent vowel. Our current research investigates effects of the (a) following vowel, (b) linguistic property of the stimulus (actual word versus nonsense word), (c) the task of the subject (identification of word versus initial consonant), and (d) presentation of no‐noise control trials (randomly mixed with noise trials versus blocked separately). The natural token stimuli were spoken by a male linguist, and digitized for later computer synthesis at equal average intensities. We found systematic errors in the perception of “p” as “t” under certain conditions, the perception of “t” as “p”...

Nearly three decades ago, Hirsh [J. Acoust. Soc. Am. 31, 759–761 (1959)] found that the threshold for identification of temporal order of onset is significantly longer than the threshold for detection of onset asynchrony, and proposed that the order identification threshold might serve as a basis for the contrast between voiced and unvoiced aspirated stop consonants in initial position. In the last decade, a number of researchers have argued that temporal order identification threshold does not play a significant role in voicing contrast. One basis for this argument against a phonetic perception role is that the 15‐ to 20‐ms range of typical order identification thresholds for simple stimuli are significantly shorter than VOT boundaries typical for synthetic stop consonants which include an initial release burst. The current research investigated the possible contribution of an initial noise burst analog as a masking stimulus. The initial noise burst shifts temporal order identification thresholds to sign...

Two experiments were conducted to identify acoustic features for speaker identity verification (SIV) that are used by humans and not by cepstral‐based algorithms. Although these algorithms generally out‐perform human listeners for randomly selected comparisons between single‐word utterances, this approach was to analyze human performance on comparisons that could not be effectively discriminated by machine. Experiment 1 showed that humans could perform at high levels of accuracy on these comparisons suggesting that either information exists that is not captured by the algorithms, or that the information is coded by the algorithms but is not used effectively. The second experiment consisted of three stimulus conditions for SIV; digitized speech signals, noise‐excited resynthesized LPC signals, and error prediction signals from the LPC. Results indicated high levels of performance in the natural and error prediction signal conditions and performance near chance in the noise excited condition, thus suggesting that the error signal provides valuable information that allows humans to distinguish between speakers. It may be possible to improve verification algorithms by adapting current models to more accurately utilize information used by human listeners.