title: Development and Technical Validation of the Mobile Based Assistive Listening System: A Smartphone-Based Remote Microphone.
abstract: OBJECTIVE
  The purpose of this research note is to describe the development and technical validation of the Mobile Based Assistive Listening System (MoBALS), a free-of-charge smartphone-based remote microphone application.
  
  
  METHODS
  MoBALS Version 1.0 was developed for Android (Version 2.1 or higher) and was coded with Java using Eclipse Indigo with the Android Software Development Kit. A Wi-Fi router with background traffic and 2 affordable smartphones were used for debugging and technical validation comprising, among other things, multicasting capability, data packet loss, and battery consumption.
  
  
  RESULTS
  MoBALS requires at least 2 smartphones connected to the same Wi-Fi router for signal transmission and reception. Subscriber identity module cards or Internet connections are not needed. MoBALS can be used alone or connected to a hearing aid or cochlear implant via direct audio input. Maximum data packet loss was 99.28%, and minimum battery life was 5 hr. Other relevant design specifications and their implementation are described.
  
  
  CONCLUSIONS
  MoBALS performed as a remote microphone with enhanced accessibility features and avoids overhead expenses by using already-available and affordable technology. The further development and technical revalidation of MoBALS will be followed by clinical evaluation with persons with hearing impairment.
authors: PhD candidate, Interunit Program on Bioengineering, São Carlos School of Engineering, University of São Paulo, São Carlos, Brazil.
authors: Esteban Alejandro
authors: EA
authors: Lopez
authors: Speech-Language Pathology and Audiology Department, Dental School of Bauru, University of São Paulo, Bauru, Brazil.
authors: Orozimbo Alves
authors: OA
authors: Costa
authors: Speech-Language Pathology and Audiology Department, Dental School of Bauru, University of São Paulo, Bauru, Brazil.
authors: Deborah Viviane
authors: DV
authors: Ferrari
mesh_terms: D006310:Hearing Aids; D034381:Hearing Loss / Q000534:rehabilitation*; D006801:Humans; D012682:Sensory Aids; D000068997:Smartphone; D012984:Software; D013067:Speech Perception; D059015:Wireless Technology