Assistive Listening Technology: in the workplace and on campus Jeremy Brassington Tuesday, 11 July 2017
Why is it hard to hear in noisy rooms? Distance from sound source Background noise continuous and intermittent Reverberation Individuals find it hard to hear what is said and lose concentration Audibility and comprehension are not the same hearing without understanding Assistive Listening Technology: In the workplace and on campus 2
Distance: The inverse square law The sound intensity from a point source of sound will obey the inverse square law if there are no reflections or reverberation. A plot of this intensity drop shows that it drops off rapidly. Assistive Listening Technology: In the workplace and on campus 3
Background Noise Continuous - traffic, equipment noise, other conversations or telephone calls etc Intermittent - coughing, door slamming, sirens Compete with the voice of the speaker Noise levels in classrooms and lecture halls 60 to 70dB Noise levels in open plan offices - 35 to 55dB Typical spoken voice range between 50 and 65dB Assistive Listening Technology: In the workplace and on campus 4
Reverberation Original sound Reverberant sound Original sound shown in red Reverberant sound shown in green In this example the reverberant sound is masking the consonant peaks The greater the reverberation in the room the lower the speech intelligibility Assistive Listening Technology: In the workplace and on campus 5
Cumulative effect In combination will lead to lower speech intelligibility Impaired Aural Focus makes it difficult to hear one sound out of several Loss of a key word can make a sentence meaningless Lose concentration Performance will suffer Assistive Listening Technology: In the workplace and on campus 6
Why do hearing aids not solve the problem? High speech to noise ratios required Quality of sound arriving at hearing aid microphone Hearing aids can amplify and process sound signals to match hearing loss Cannot replace missing words or syllables Physical position of microphone Assistive Listening Technology: In the workplace and on campus 7
Challenges in the workplace and on campus Meetings and workshop groups Telephone conversations Conferences and courses Interaction with customers in retail environments Conversations in noisy open plan offices Note-taking in lectures and meetings High noise level environments which compete with the volume level of the speaker Low speech to noise ratio Assistive Listening Technology: In the workplace and on campus 8
Effects of hearing loss Resort to lip reading Increased stress levels where cannot hear properly Reduced understanding if words unclear Extra effort to communicate and learn Reluctance to admit lack of hearing Assistive Listening Technology: In the workplace and on campus 9
What is the solution? Use Assistive Listening Technology to amplify the speaker s voice and separate it from the ambient noise Deliver the speaker s voice directly to the person using a hearing aid or headphones /earphones Eliminate distractions allowing individual to focus on speaker s voice Assistive Listening Technology: In the workplace and on campus 10
Assistive Listening Equipment requirements Capture the speech signal Deliver that signal to the individual with hearing loss Amplification Strong signal to noise ratio Good directionality Low distortion In combination these will enhance the speech to noise experience of the individual and improve comprehension ability Assistive Listening Technology: In the workplace and on campus 11
Different Types of Assistive Listening Technology Inductive Room Loop Amplified Listeners Wireless Assistive Listening Devices ( ALDs ) Note-taking solutions and Directional Microphones Assistive Listening Technology: In the workplace and on campus 12
Inductive room loop Loop of wire encircles listening area connected to amplifier output of sound system Hearing aid acts as the receiver through the Telecoil setting Fixed installation Only used for individuals who are wearing a hearing aid. Not portable from room to room. Assistive Listening Technology: In the workplace and on campus 13
Amplified Listeners Directional microphone and sound amplification Can be used with hearing aid or headphones/earphones Speaker s voice is amplified but any noise between speaker and listener will also be amplified Listener needs to be close to speaker or in a small room Can be used to amplify telephone conversations Limited to use in one to one or small meeting rooms and telephone amplification Assistive Listening Technology: In the workplace and on campus 14
Wireless ALDs Wireless ALDs use a microphone transmitter which is worn or held by the speaker FM Radio, Infrared or Bluetooth devices are available The speaker s voice is broadcast to one or more receivers worn by the hearing impaired employee Individual listens to speaker s voice through hearing aid or headphones/earphones Dramatically improves speech to noise levels and increases speech intelligibility Most suitable type of system for hearing impaired individuals in meeting rooms, conference halls and noisy environments. Assistive Listening Technology: In the workplace and on campus 15
FM Radio Systems Speaker s voice is broadcast to one or more receivers worn by the individuals who need hearing assistance-like a one way walkie-talkie Individuals listen through hearing aid or headphones/earphones Range of up to 50m indoors and up to 100m outdoors suitable for large venues Can be connected to TV or sound system Tried and tested reliable system of communication for the hearing impaired user. Assistive Listening Technology: In the workplace and on campus 16
Bluetooth Systems Wireless bluetooth available for connection to mobile phones, computers and TVs Limited range so not ideal for large rooms Higher battery usage Some latency issues with lip reading and sound transmission not synchronised Expensive Used for small groups where connection to TV, mobile phone and computers is important. Assistive Listening Technology: In the workplace and on campus 17
Infrared Systems Speaker s voice is broadcast to one or more receivers worn by the individuals who need hearing assistance using Infrared signal-like a TV controller Individuals listen through hearing aid or headphones/earphones Cannot be used where there are obstructions or partitions in the lecture hall Not suitable for outdoors or large venues Can be connected to TV or sound system Used for small groups indoors where there are no obstructions. Most often used as TV listeners. Assistive Listening Technology: In the workplace and on campus 18
Note-taking Solutions Use DVR or recording App and directional microphone Note-taking software to edit and collate notes Remote notetaking assistance Matching notes to audio recording Reduce stress Used by hard of hearing and individuals with SpLDs at university Assistive Listening Technology: In the workplace and on campus 19
Summary High ambient noise level and poor room acoustics Position of the microphone is key Note-taking solutions can improve understanding Inclusion Wireless microphones can improve intelligibility Stress reduction Assistive Listening Technology: In the workplace and on campus 20
Thank you For more information go to www.conversorproducts.com Assistive Listening Technology: In the workplace and on campus 21
Making communication clearer