Indoor-Guided Navigation for People Who Are Blind: Crowdsourcing for Route Mapping and Assistance

This paper presents an approach to enhance electronic traveling aids (ETAs) for people who are blind and severely visually impaired (BSVI) using indoor orientation and guided navigation by employing social outsourcing of indoor route mapping and assistance processes. This type of approach is necessary because GPS does not work well, and infrastructural investments are absent or too costly to install for indoor navigation. Our approach proposes the prior outsourcing of vision-based recordings of indoor routes from an online network of seeing volunteers, who gather and constantly update a web cloud database of indoor routes using specialized sensory equipment and web services. Computational intelligence-based algorithms process sensory data and prepare them for BSVI usage. In this way, people who are BSVI can obtain ready-to-use access to the indoor routes database. This type of service has not previously been offered in such a setting. Specialized wearable sensory ETA equipment, depth cameras, smartphones, computer vision algorithms, tactile and audio interfaces, and computational intelligence algorithms are employed for that matter. The integration of semantic data of points of interest (such as stairs, doors, WC, entrances/exits) and evacuation schemes could make the proposed approach even more attractive to BVSI users. Presented approach crowdsources volunteers’ real-time online help for complex navigational situations using a mobile app, a live video stream from BSVI wearable cameras, and digitalized maps of buildings’ evacuation schemes.

SpEx: A Tool for Visualising and Navigating Speech Audio

<p>Audio is a ubiquitous form of information that is usually treated as a single, unbreakable, piece of content. Thus, audio interfaces remain simple, usually consisting of play, pause, forward, and rewind controls. Spoken audio can contain useful information across multiple topics and finding the information desired is usually time consuming. Most audio players simply do not reveal the content of the audio. By using the speech transcript and acoustic qualities of the audio, I have developed a tool, SpEx, which enabled search and navigation within spoken audio. SpEx displayed audio as discrete segments and revealed the topic content of each segment using mature Information Visualisation techniques. Audio segments were produced based on the acoustic and sentence properties of speech to identify topically and aurally distinct regions. A user study found that SpEx allowed users to find information in spoken audio quickly and reliably. By making spoken audio more accessible, people can gain access to a wider range of information.</p>

SpEx: A Tool for Visualising and Navigating Speech Audio

<p>Audio is a ubiquitous form of information that is usually treated as a single, unbreakable, piece of content. Thus, audio interfaces remain simple, usually consisting of play, pause, forward, and rewind controls. Spoken audio can contain useful information across multiple topics and finding the information desired is usually time consuming. Most audio players simply do not reveal the content of the audio. By using the speech transcript and acoustic qualities of the audio, I have developed a tool, SpEx, which enabled search and navigation within spoken audio. SpEx displayed audio as discrete segments and revealed the topic content of each segment using mature Information Visualisation techniques. Audio segments were produced based on the acoustic and sentence properties of speech to identify topically and aurally distinct regions. A user study found that SpEx allowed users to find information in spoken audio quickly and reliably. By making spoken audio more accessible, people can gain access to a wider range of information.</p>

It's About Time: Minimizing Hardware and Software Latencies in Speech Research With Real-Time Auditory Feedback

Purpose Various aspects of speech production related to auditory–motor integration and learning have been examined through auditory feedback perturbation paradigms in which participants' acoustic speech output is experimentally altered and played back via earphones/headphones “in real time.” Scientific rigor requires high precision in determining and reporting the involved hardware and software latencies. Many reports in the literature, however, are not consistent with the minimum achievable latency for a given experimental setup. Here, we focus specifically on this methodological issue associated with implementing real-time auditory feedback perturbations, and we offer concrete suggestions for increased reproducibility in this particular line of work. Method Hardware and software latencies as well as total feedback loop latency were measured for formant perturbation studies with the Audapter software. Measurements were conducted for various audio interfaces, desktop and laptop computers, and audio drivers. An approach for lowering Audapter's software latency through nondefault parameter specification was also tested. Results Oft-overlooked hardware-specific latencies were not negligible for some of the tested audio interfaces (adding up to 15 ms). Total feedback loop latencies (including both hardware and software latency) were also generally larger than claimed in the literature. Nondefault parameter values can improve Audapter's own processing latency without negative impact on formant tracking. Conclusions Audio interface selection and software parameter optimization substantially affect total feedback loop latency. Thus, the actual total latency (hardware plus software) needs to be correctly measured and described in all published reports. Future speech research with “real-time” auditory feedback perturbations should increase scientific rigor by minimizing this latency.

Design of a Linear Voltage to Frequency Converter for Digital Audio Applications

Voltage to frequency converters are used in various types of analog to digital converters in suitable digital audio applications. One of the applications is the Audio Interface which has been considered. The Voltage to frequency converter (VFC) thus plays a major role in the analog to digital conversion. This paper proposes a low power VFC designed in 0.18 µm technology which in turn is used to design a low cost and a high-resolution analog to digital converter (ADC). The analog signal is given to the V-F converter and the VFC output is given to the frequency counter using a suitable link. This counter gives the digital output. The design is implemented in PSoC and the performance is analysed with the previous technologies. Parameters such as sensitivity, output frequency and power consumption are analysed. This V-F converter and ADC are used in the digital audio interface which is used for audio applications. With the proposed VFC and ADC, the interface produced a good SNR compared to the conventional audio interfaces.

Consumer-Grade Headphones for Children: Limited Effectiveness of “Level Limiters” When Used With Portable or Home Media Players

Consumer-grade headphones for children are frequently packaged or marketed with labels claiming incorporation of an output-level-limiting function. Six pairs of headphones, sold separately from devices with audio interfaces, were selected either from online recommendations or from “best rated” with a large online retailer, the opinions being expressed in 2018 to early 2019. The acoustic outputs in response to an internationally standardized test signal were measured through the ears of a head-and-torso simulator and referenced to equivalent A-weighted diffuse-field sound pressure levels. The headphones were tested with a variety of music capable sources found in a domestic environment, such as a mobile phone, tablets, laptop computer, and a home “hi-fi” CD player. To maintain likely homogeneity of the audio interface, the computer-based platforms were manufactured by either Apple™ or certified Android devices. One of the two Bluetooth-linked headphones exhibited level limiting with low distortion (i.e., a compression ratio well in excess of unity). None of the devices wired directly to an audio output performed distortionless level limiting: “limiting” was implemented by a reduction of sensitivity or mechanical limitations, so could be called “soft limiting.” When driven by a laptop or CD player, some were still capable of producing output levels well in excess of “safe-listening” levels of 85 dB(A). Packaging labels were frequently ambiguous and imprecise.