Portable Audio Device Research Articles

Wireless Power Hanger Pad for Portable Wireless Audio Device Power Charger Application

Since the portability feature has been introduced in headphone development, this device now uses a battery as the main built-in power. However, the battery has limited power capacity and a short lifetime. Battery substitution and a conventional battery charger method is an ineffective, inflexible inconvenience for enhancing the user experience. This paper presents an innovative portable audio device battery built-in charger method based on wireless power technology. The developed charging device is composed of a headphone hanger pad for the wireless headphone and a charging pad for the portable wireless audio device battery charging. Circular flat spiral air-core coil was designed and evaluated using a numerical method to obtain optimal vertical magnetic field distribution based on the proposed evaluation criteria. A coil has inner coil diameter of 25 mm, outer coil diameter of 47.8 mm, wire diameter of 0.643 mm, the pitch of 0.03 mm and a number of turns of 17 was chosen to be implemented on the transmitter coil. A magnetic induction technique was adopted in the proposed wireless power transmission module which was implemented using commercial off-the-shelf components. For experimental and validation purposes, a developed receiver module applied to the commercial wireless headphone and portable audio speaker have a built-in battery capacity at 3.7 V 300 mAh. The experimental results show that the wireless power hanger pad prototype can transfer a 5 V induction voltage at a maximum current of 1000 mA, and the power transfer efficiency is around 70%. It works at 110 kHz of operation frequency with a maximum transmission distance of about 10 mm and takes 1 h to charge fully one 3.7 V 300 mAh polymer lithium battery.

Relationship between the use of portable audio devices and taking notice of the approach informing sound of quiet vehicles

Lively discussion about the approach informing sound of quiet vehicles is being conducted; however, people often listen to media on portable audio devices in various environments and may not notice the approach informing sound. To clarify the relationship between the use of portable audio devices and the experience of encountering dangers associated with the approach of quiet vehicles, a questionnaire survey was conducted with 158 university students. Portable audio device ownership was 99.3%; only one respondent reported not owning such a device. Twenty-two respondents (15.5%) had encountered dangerous situations while using these devices outdoors. Thirteen respondents reported that they had experienced near-misses with vehicles while walking or biking, and seven reported that the vehicles were quiet vehicles. Multiple correspondence analysis revealed some differences in the usage habits of portable audio devices between the users who had and had not encountered dangerous situations. To improve notification effectiveness of quiet vehicles, usage habits related to portable audio devices, especially concerning young people, should be considered. In addition, means of preventing portable audio device users’ tendency to “tune out” other sounds should be addressed.

Electromechanical cell lysis using a portable audio device: enabling challenging sample preparation at the point-of-care.

Audio sources are ubiquitously available on portable electronic devices, including cell phones. Here we demonstrate lysis of Mycobacterium marinum and Staphylococcus epidermidis bacteria utilizing a portable audio device coupled with a simple and inexpensive electromagnetic coil. The resulting alternating magnetic field rotates a magnet in a tube with the sample and glass beads, lysing the cells and enabling sample preparation for these bacteria anywhere there is a cell phone, mp3 player, laptop, or other device with a headphone jack.

The Effectiveness of Portable Audio Biofeedback Device in Myofascial Pain Syndrome in Neck and Upper Trapezius Muscles

AbstractObjective: The aim of this study was to investigate the effectiveness of a portable audio biofeedback device in the treatment of myofascial pain syndrome [MPS].Methods: Patients referred to the clinic with MPS involving the upper neck and trapezius who were were randomly assigned into two groups. Group 1 was to use a portable audio biofeedback device for 30 min twice a day in addition to completing a home based exercise program. Group 2 received only the home-based exercise program. The home-based exercise program was comprised of neck isometric-isotonic, back extensor stretching and posture exercises five times a week, performing each exercise once a day with 15 repetitions for 4 weeks. Measurements were taken before and after the treatment. The severity of the pain was measured by visual analog scale. The number of trigger points, pressure pain threshold, cervical joint range of motion and head-shoulder angles were also recorded. Disability was assessed by the Neck Pain Disability Scale.Results:...

PORTABLE SOUND REPRODUCING SYSTEM AND METHOD

A portable audio device suitable for reproducing MPEG encoded data includes a plurality of inputs, a data storage, a display, an audio output, at least one processor, and a battery. The plurality of inputs includes a forward input, a play control input, and a random input. The data storage stores compressed digitized audio data. The at least one processor is responsive to selection of at least one of the plurality of inputs to convert selected compressed digitized audio data stored in the data storage for reproduction by the audio output and to provide information to the display.

METHOD AND APPARATUS TO CONTROL OUTPUT POWER OF A DIGITAL POWER AMPLIFIER OPTIMIZED TO A HEADPHONE AND A PORTABLE AUDIO PLAYER HAVING THE SAME

A method and apparatus to control output power of a digital amplifier capable of automatically determining an impedance of an earphone or headphone connected to a portable audio device and outputting a power that is optimized according to the impedance. The apparatus is usable with a digital amplification device and includes a signal processing unit to convert a pulse signal into a direct current (DC) voltage by power-amplifying the pulse signal, an impedance measuring unit to connect a resistance device between the signal processing unit and a speaker unit and to detect a voltage value applied to the resistance device and the speaker unit, and a micom unit to generate a pulse signal having a predetermined duty cycle in the signal processing unit if the speaker unit is connected to the device, to determine an impedance of the speaker unit based on the voltage value detected by the impedance measuring unit, to control a power amplification by providing a voltage level control signal to the signal processing unit according to the determined impedance, and to control an audio level in an audio reproduction mode accordingly.

Ear diseases among secondary school students in Xi'an, China: The role of portable audio device use, insomnia and academic stress

BackgroundHearing impairment negatively impacts students' development of academic, language and social skills. Even minimal unilateral hearing loss can hinder educational performance. We investigated the prevalence of ear diseases among secondary school students in the city of Xi'an, China in order to provide a foundation for evidence-based hearing healthcare.MethodsA stratified random sampling survey was conducted in 29 secondary schools. Demographics and medical histories were collected, and otologic examinations were performed. Questionnaires were administered to assess insomnia, academic stress and use of portable audio devices. Logistic regression analysis was used to identify factors associated with hearing impairment, and the association of sensorineural hearing loss with insomnia, academic stress and the use of portable audio devices was analyzed with the chi-square test.ResultsThe percentage of students with some form of ear disease was 3.32%. External ear disease, middle ear disease and sensorineural hearing loss occurred in 1.21%, 0.64% and 1.47% of the students, respectively. Boys had a relatively higher prevalence of ear disease than girls. According to our survey, the prevalence of sensorineural hearing loss increased significantly among the students with insomnia and extended use of portable audio devices, but not among those with elevated levels of academic stress. Hearing aids and surgical treatment were needed in 1.47% and 0.89% of the students, respectively.ConclusionsThere is a high prevalence of ear disease among secondary school students, and this should be given more attention. Insomnia and the excessive use of portable audio devices may be related to adolescent sensorineural hearing loss. It is important to establish and comply with an evidence-based preventive strategy.

Sound Enhancing Stands for Portable Audio Devices

Stands for a portable audio device include a housing and a mounting member. The mounting member is configured to couple the audio device to the housing at a location selected to reflect sounds generated by a speaker of the audio device away from the housing. Stands may include a resonator cavity in the housing with an outlet opening extending to the resonator cavity from an exterior surface of the housing and a volume of the resonator cavity and a size of the outlet opening extending thereto may be selected to provide a desired resonant frequency response of the resonator cavity to amplify sounds generated by the speaker of the audio device.

Double wire cord and portable audio device using the same

A double wire cord is used in an electro-acoustic converter, such as earphones and headphones, and has a long first cord and a long second cord. For example, the first cord is substantially circular in cross section and has a large diameter, the second cord is also substantially circular in cross section and has a small diameter, and the second cord can be removably housed in the first cord. The second cord is fitted into the fitting groove of the first code and thus housed in the first cord by pressing the side surface of the second cord against the fitting groove of the first cord, so that one wire cord can be easily provided. Therefore, it is convenient at the time of use and storage.

Sports helmet having integral speakers

A sports helmet includes a liner comprised of impact resistant material and a protective shell encasing an outer surface of the liner. A female audio jack is secured within a rear cavity of the liner and has an aperture extending without the liner for receiving a male audio jack connected to a portable audio device. A pair of cavities are formed on opposite sides of the liner in which are secured speakers. Wiring extends from the female audio jack to the integral speakers. The speakers are positioned and oriented such so as to provide audio to the helmet wearer without blocking surrounding sound, and without affecting the safety aspects of the helmet.

High Performance Magnetic Head for MiniDisc System

A compact and thin magnetic head is indispensable in obtaining a compact MiniDisc (MD) system for both a portable audio device and a computer data storage device. Double speed recording operation is also important. To satisfy the requirements, we have developed a compact and thin magnetic head for MD system by optimizing the core shape with a high magnetic flux efficiency. This head adopts a newly developed low loss Mn-Zn ferrite for the head core. The magnetic head enables double speed recording operation from 400 kHz to 1.44MHz at the disk velocity of 2.8m/s, in addition to stable following ability and sliding durability to the disk rotation.

Personal portable audio device

A personal portable audio device includes a garment having a pocket, a speaker is provided at the shoulder portions of the garment, audio components located in the garment pockets, and lead wires are arranged in the garment for connecting the audio components with the speakers.