A bluetooth development tool has helped Sound ID to produce a headset for the hard of hearing which employs wireless communications to link an in-ear module with a remote microphone.
The xIDE software development kit from Cambridge Consultants allowed Sound ID to eliminate the need for a separate microprocessor in its in-ear headset. They did this by exploiting the ‘free’ processor that comes as part of the bluetooth chip to control the overall hearing system. This resulted reduced cost and power consumption power consumption.
Sound ID’s Personal Sound System looks like a small bluetooth mobile phone headset. Inside the device is a digital signal processor (DSP) that can be configured by an audiologist, or the user, to amplify sound based on individual preferences. The bluetooth capability allows the ear module to link with a remote microphone that can be positioned to improve signal-to-noise ratio. It also acts as a standard bluetooth headset for a mobile phone, automatically switching from continuous amplification mode to hands-free mode when a call is in progress.
The processor in Sound ID’s ear has to run four types of Bluetooth application software: hands free and headset profiles for open connectivity with mobile phones, a custom profile that passes audio between the companion microphone and ear module, and a serial port profile for connecting to a PC for initial configuration. In addition, the processor controls the overall system, including the DSP, and user interface buttons and beeper. This includes managing configuration software that allows the DSP’s amplification and spectral shaping characteristics to be personalised, and different sound settings to be selected during use.
The ability to perform all these functions was made possible by Cambridge Consultants’ xIDE software development kit. This gives unrestricted access to the full native power of the processor inside BlueCore chip used, allowing developers to bypass a software layer that usually serves to protect the Bluetooth compliance of the chip.