Personal Communication Link and Assistive Services

Acoustic transmission is often not sufficient to ensure receipt of all information for persons in adverse listening conditions or when having a hearing impairment. In particular when using hearing devices, existing assistive devices designed for hearing impaired persons fall short in performance, quality, flexibility and also do not allow an easy adaptation to new developments.

The inductive loop is a common standard in use for hearing devices since long time. However it has several drawbacks: the audio quality is low, interference from other magnetic sources is a general problem and security is non-existent. Later developed systems, such as IR and FM, get over some shortcomings, but are not very flexible, proprietary and not compatible with other systems.

It is the vision that recent developments on wireless communication and handheld processing power (mobile phones, PDA, small notebooks) will enable the implementation of powerful communication tools and make them available at low prices for a large public. These developments on mainstream technology will be an ongoing process in which the incorporation of the needs for assisted communication for hearing and communication can and should be included.

The target group for assisted communication consists of persons that have mild to severe problems on hearing and communication. The origin of these communication problems can range from adverse ambient conditions (for instance by interfering sounds and information) up to severe hearing disabilities of the hearing organ.

Hearing and communication assistance can be provided to a potentially large target group of persons that need or prefer communication assistance. To achieve this the person must be willing to wear an assistive hearing device ranging from a standard headset up to an advanced hearing aid or cochlear implant. By modern technology these devices can be worn more and more unobtrusively by its miniature size, ease of access and the prospective wireless connections to other systems.

Subproject SP4 has been set up as part of the HearCom Project to focus on the specification and demonstration of new assistive applications, based on new technologies and innovations that can be of benefit to hearing and communication tasks.

General objective of SubProject 4 is to investigate the feasibility of novel technologies to improve hearing and communication. These technologies are:

  • Personal Communication Link (PCL). A wireless communication link to be integrated in hearing devices. This will be based on a Body Area Network (BAN) technology.
  • Personal Communication System (PCS) serving as a concentrator that bridges between the PCL (BAN) and outside communication networks such as the Personal Area Network (PAN) and the Wide Area Network (WAN). The PCS will be the platform for new assistive functions that will assist in hearing and communication.

On the basis of the PCL and PCS the following assistive applications have been investigated in the HearCom project:

  • Personal Hearing System (PHS) that assists on hearing using the PCL and that can be integrated into the PCS .
  • Wireless Public Address (WPA) that provides textual and auditive announcement information on the PCS.
  • Automatic Speech Recognition (ASR), a future application for use to assist on speech communication integrated in the PCS. The target implementation will be based on a client server approach.
  • Bimodal integration of speech and text. Investigation on the combination of textual and auditive information for the PCS in which both information sources may have inherent errors (speech recognition errors, acoustic noise). When both imperfect sources are combined this may provide sufficient information to understand what has been said.