Hi Pragati,

there are quite a few studies, I have listed the URL to a few below.

But  I wonder what its utility would be. All it will do is lead to is lead to a larger response if at all. Though it will lead tot larger amplitudes it will not aid in improving the clinical situation. Here are my views:

1. It is a broad band signal and not frequency specific. 

2. If at all you want to use an NB chirp, it will solve the frequency specificity problem and should be fair enough for threshold estimation. But other applications like hearing aid assessment cannot be carried out due to the transient nature of the stimulus. I feel that the real strength of ASSR is the continuous nature of the stimulus, and using repetition rate related MLRs using transient responses really doesn't replace substitute the real ASSRs.

Why cant Modulated NB noises serve the purpose  ???

regards, 

Nike

Links to articles below

http://www.ijporlonline.com/article/S0165-5876(14)00093-7/abstract

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1020645&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1020645

http://www.ncbi.nlm.nih.gov/pubmed/24613039

http://dtic.mil/dtic/tr/fulltext/u2/a410106.pdf

http://scholarlyrepository.miami.edu/dissertations/2016/

Hi Pragati,

we use in our clinic NB CE Chirps in ASSR for about 4 years for frequency specific threshold estimation in young children with excellent results. In our experience NB CE Chirps ( narrow band Claus Eberling Chirps)  and more recently level specific NB CE Chirps (LS CE Chirps) permit reliable thresholds and time-saving frequency specific testing, particularly in the normal hearing range or for mild and moderate hearing loss.  When recording conditions are adequate ( smooth EEG, deeply sleeping child or under light anesthesia) the test can be completed in about 10 to 30 minutes. Both air conducted and bone conducted frequency specific stimulation is possible.

I do not recommend NB CE Chirps for high intensity stimulation ( > 80 dB HL), as the stimulus  was not designed for these intensities, hopefully it will be developped soon... In chidren with severe-to profound hearing loss I use the MASTER II software ( Natus, Bio-logic)  with an AM/FM stimulus which permits frequency-specific threshold estimation  in high intensities where transient stimuli like clicks or tone bursts may not be helpful (saturation).

Best regards,

Signe Grasel

As indicated by others,  threshold assessment using CE Chirps doesn't makes sense due to its broadband (no frequency specificity)  nature.  Of course,  many do still persist using broadband stimuli (i. e.,  clicks) for their ABR thresholds -- unfortunately.

Regarding NB chirps: I do not believe there has been a full/good comparison of their frequency specificity compares to brief tones,  especially in steeper SNHL. The acoustic spectra of NB Chirps appear broader than 5-cycle brief tones.

Finally,  regarding ASSRs (80-110 Hz) not being "transient"  responses: there is some evidence to suggest they actually are transient responses and do not reflect the whole stimulus (i. e.,  the response is evoked by the early portion of the stimulus, similar to ABR wave V) .

The is another issue with chirps and ASSRs as diagnostic tools-- very little bone-conduction data -- only one conference paper on BC NB chirp data at 500 Hz which  identified more non-linearities than reported for other types of BC stimuli-- this problem needs to be looked at further. and resolved before NB chirps can be implemented fully like the brief-tone ABR.

Hi Pragati,

You may want to read this recent article

Assessment of low-frequency hearing with narrow-band chirp-evoked

40-Hz sinusoidal auditory steady-state response

Uzma S. Wilson, Wafaa A. Kaf, Ali A. Danesh & Jeffery T. Lichtenhan

Pages: 1-9

http://www.tandfonline.com/doi/full/10.3109/14992027.2015.1122238?ai=1vvos&ui=8b80c&af=T

The above-referenced Wilson et al.,  2015 IJA paper concerns the 40-Hz ASSR (vs tone ABR)  in awake adults with normal hearing.  Its results are likely less applicable to infants.

Hi,

I just saw an  article on ASSRs using NB chirps. I think it is relevant for this thread, and will stimulate further discussion.

Comparison of threshold estimation in infants with hearing loss or normal hearing using auditory steady-state response evoked by narrow band CE-chirps and auditory brainstem response evoked by tone pips

Franck Michel & Kristoffer Foldager Jørgensen

Pages 99-105 | Received 22 Feb 2016, Accepted 06 Sep 2016, Published online: 07 Oct 2016

http://www.tandfonline.com/doi/full/10.1080/14992027.2016.1234719