Acoustic Features Distinguishing Emotions in Swedish Speech.

Few studies have examined which acoustic features of speech can be used to distinguish between different emotions, and how combinations of acoustic parameters contribute to identification of emotions. The aim of the present study was to investigate which acoustic parameters in Swedish speech are most important for differentiation between, and identification of, the emotions anger, fear, happiness, sadness, and surprise in Swedish sentences. One-way ANOVAs were used to compare acoustic parameters between the emotions and both simple and multiple logistic regression models were used to examine the contribution of different acoustic parameters to differentiation between emotions. Results showed differences between emotions for several acoustic parameters in Swedish speech: surprise was the most distinct emotion, with significant differences compared to the other emotions across a range of acoustic parameters, while anger and happiness did not differ from each other on any parameter. The logistic regression models showed that fear was the best-predicted emotion while happiness was most difficult to predict. Frequency- and spectral-balance-related parameters were best at predicting fear. Amplitude- and temporal-related parameters were most important for surprise, while a combination of frequency-, amplitude- and spectral balance-related parameters are important for sadness. Assuming that there are similarities between acoustic models and how listeners infer emotions in speech, results suggest that individuals with hearing loss, who lack abilities of frequency detection, may compared to normal hearing individuals have difficulties in identifying fear in Swedish speech. Since happiness and fear relied primarily on amplitude- and spectral-balance-related parameters, detection of them are probably facilitated more by hearing aid use.

Interaction between osseous and non-osseous vibratory stimulation of the human cadaveric head.

Bone conduction (BC) stimulation can be applied by vibration to the bony or skin covered skull (osseous BC), or on soft tissue such as the neck (non-osseous BC). The interaction between osseous and non-osseous bone conduction pathways is assessed in this study. The relation between bone vibrations measured at the cochlear promontory and the intracranial sound pressure for stimulation directly on the dura and for stimulation at the mastoid between 0.2 and 10 kHz was compared. First, for stimulation on the dura, varying the static coupling force of the BC transducer on the dura had only a small effect on promontory vibration. Second, the presence or absence of intracranial fluid did not affect promontory vibration for stimulation on the dura. Third, stimulation on the mastoid elicited both promontory vibration and intracranial sound pressure. Stimulation on the dura caused intracranial sound pressure to a similar extent above 0.5 kHz compared to stimulation on the mastoid, while promontory vibration was less by 20-40 dB. From these findings, we conclude that intracranial sound pressure (non-osseous BC) only marginally affects bone vibrations measured on the promontory (osseous BC), whereas skull vibrations affect intracranial sound pressure.

Adult hearing screening: follow-up and outcomes1.

PURPOSE: To screen hearing and evaluate outcomes in community-dwelling older adults. METHOD: Three thousand and twenty-five adults responded to an invitation to be screened by questionnaire, otoscopy, and pure-tone audiometry. Pure-tone average (PTA) >35 dB HL in the worse ear, unilateral hearing loss, or otoscopic findings were the criteria for referral for services. A questionnaire related to compliance with referral recommendations was completed by telephone interview for 160 randomly selected participants after 1-2 years from referral. RESULTS: The referral rate for audiologic/hearing aid evaluation was 46%, and referral for cerumen removal/medical evaluation was 17%. Of the people referred for audiologic/hearing aid evaluation, 18% tried a hearing aid; 2 years later, 11% were using a hearing aid. Screening recommendations affected participants' decision to seek help. Study participants stated that the screening was helpful, it should be offered to everybody, and they would participate in future screenings. CONCLUSION: Although adult hearing screening offered timely identification of hearing loss for adults seeking help, follow-up with hearing aid treatment was low.

e-Health Technologies for Adult Hearing Screening.

The development of hearing diagnosis methods and hearing screening methods are not isolated phenomena: they are intimately related to changes in the cultural background and to advances in fields of medicine and engineering. In the recent years, there has been a rapid evolution in the development of fast, easy and reliable techniques for low-cost hearing screening initiatives. Since adults and elderly people typically experience a reduced hearing ability in challenging listening situations [e.g., in background noise, in reverberation, or with competing speech (Pichora-Fuller & Souza, 2003)], these newly developed screening tests mainly rely on the recognition of speech stimuli in noise, so that the real experienced listening difficulties can be effectively targeted (Killion & Niquette, 2000). New tests based on the recognition of speech in noise are being developed on portable, battery-operated devices (see, for example, Paglialonga et al., 2011), or distributed diffusely using information and communication technologies. The evolutions of e-Health and telemedicine have shifted focus from patients coming to the hearing clinic for hearing health evaluation towards the possibility of evaluating the hearing status remotely at home. So far, two ways of distributing the hearing test have primarily been used: ordinary telephone networks (excluding mobile networks) and the internet. When using the telephone network for hearing screening, the predominantly test is a speech-in-noise test often referred to as the digit triplet test where the subjects hearing status is evaluated as the speech-to-noise threshold for spoken digits. This test is today available in some ten countries in Europe, North America and Australia. The use of internet as testing platform allows several different types of hearing assessment tests such as questionnaires, different types of speech in noise tests, temporal gap detection, sound localization (minimum audible angle), and spectral (un)masking tests. Also, the use of the internet allows audiovisual presentations as well as visual interaction and cues in the tests for a more ecological approach. Even if several new and novel approaches for hearing assessment using the internet are surfacing, the validated tests are based on questionnaires or speech-in-noise. Although the internet allows for a broader flora of pure auditory and audiovisual tests for hearing health assessment, calibration problems such as timing uncertainty, output levels and modes of presentation (speakers or earphones) limits the usability at present.

Acoustic role of the buttress and posterior incudal ligament in human temporal bones.

OBJECTIVES: In middle ear surgery using intact ear canal wall techniques, the buttress, which is the bony bridge at the medial end of the posterior-superior bony ear canal, is commonly retained during posterior tympanotomy. In some cases, the surgical exposure may be improved by resectioning the buttress, and this requires sectioning the posterior incudal ligament. To date, the acoustic effects of removing the buttress with sectioning of the attached ligament have not been studied. METHOD: Using a laser Doppler vibrometer system, 15 human cadaver temporal bones were measured with 80 dB sound pressure level at the tympanic membrane over the 0.1 to 10 kHz frequency range. RESULT: The resection of the buttress and sectioning the posterior incudal ligament had no effect on stapes footplate velocity. CONCLUSION: These results suggest that the posterior incudal ligament does not play a significant role in the acoustic function of the ossicles.

A bone-anchored hearing aid for patients with pure sensorineural hearing impairment: a pilot study.

This pilot study assesses the potential benefits of an optimized bone-anchored hearing aid (BAHA) for patients with a mild to moderate pure sensorineural high frequency hearing impairment. The evaluation was conducted with eight first-time hearing aid users by means of psycho-acoustic sound field measurements and a questionnaire on subjective experience; all of the patients benefited from the BAHA. On average, the eight patients showed improvement in PTA threshold of 3.4 dB and in speech intelligibility in noise of 14%. Seven of the subjects, also fitted with present standard air conduction hearing aids (ACHA) found the ACHA thresholds to be improved more than the BAHA ones. In speech tests, the ACHA was only slightly better; these patients chose between their different hearing aids according to the sound environment. Although the BAHA was preferred for wearing and sound comfort, it cannot be used as the sole aid for patients with pure sensorineural impairment.

Vibration characteristics of bone conducted sound in vitro.

A dry skull added with damping material was used to investigate the vibratory pattern of bone conducted sound. Three orthogonal vibration responses of the cochleae were measured, by means of miniature accelerometers, in the frequency range 0.1-10 kHz. The exciter was attached to the temporal, parietal, and frontal bones, one at the time. In the transmission response to the ipsilateral cochlea, a profound low frequency antiresonance (attenuation) was found, verified psycho-acoustically, and shown to yield a distinct lateralization effect. It was also shown that, for the ipsilateral side, the direction of excitation coincides with that of maximum response. At the contralateral cochlea, no such dominating response direction was found for frequencies above the first skull resonance. An overall higher response level was achieved, for the total energy transmission in general and specifically for the direction of excitation, at the ipsilateral cochlea when the transducer was attached to the excitation point closest to the cochlea. The transranial attenuation was found to be frequency dependent, with values from -5 to 10 dB for the energy transmission and -30 to 40 dB for measurements in a single direction, with a tendency toward higher attenuation at the higher frequencies.

Sensitivity to bone-conducted sound: excitation of the mastoid vs the teeth.

The sensitivity of nine subjects to bone-conducted sound was measured at three positions: osseointegrated percutaneous titanium implants in the temporal bone, the skin-covered mastoid and the teeth. Voltage levels supplied to a bone-anchored hearing aid (BAHA) transducer and to an Oticon bone-transducer were measured and the thresholds obtained at the three positions were compared. Using the mechanical impedance of the teeth, the parameters of a first order model for the vibration transmission through the teeth was calculated. Also, the equivalent force thresholds were calculated from the voltage threshold levels. The sensitivity to bone-conducted sound, for both voltage and force thresholds, conformed fairly well at the three positions for frequencies below 1 kHz; however, above 1 kHz, bone-conducted sound applied at the titanium implant becomes more sensitive than at the two other positions investigated. It was concluded that the teeth can be used for the application of bone-conducted sound, in particular for pre-operative assessment of a BAHA and to facilitate service and quality control of such a hearing device.

A miniaturized artificial mastoid using a skull simulator.

A miniaturized artificial mastoid of size and weight that allow calibration and measurement of bone conduction hearing aids in a conventional audiometric soundproof box has been developed. Its level of mechanical impedance corresponds to the standard IEC 373 (1990) within the frequency range 250 Hz to 8 kHz. The miniaturized artificial mastoid consists of three parts: coupler, skull simulator (TU-1000), and an external electrical correction filter. The coupler is a highly damped mass-spring system designed to give the miniaturized artificial mastoid mechanical impedance in accordance with the standard IEC 373 (1990). It was found that the miniaturized artificial mastoid yielded results that are in correspondence with results obtained with the Brüel & Kjaer type 4930 artificial mastoid for frequencies above 450 Hz. Thus, at these frequencies, the miniaturized artificial mastoid can be used for audiometer calibration as well as measurement of bone conduction hearing aids.

Linearity of sound transmission through the human skull in vivo.

The linearity of sound propagation through the human skull was investigated. One male subject, equipped with bilateral skin-penetrating titanium fixtures for attachment of bone-anchored hearing aids, was studied thoroughly. Three different methods were used: comparison of the frequency response functions estimated at different signal levels (using stepped sine as well as random noise), comparison of the coherence function at different signal levels (using random noise), and the Hilbert transform of the estimated frequency response function. Frequencies from 0.1 to 10 kHz and signal levels up to 77 dB HL at discrete frequencies were used. No indication of any significant nonlinear behavior was found with the three methods used.