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In adults with mild to severe hearing loss, strong evi-
dence shows that the use of FM systems results in better
speech understanding in noise than the use of hearing aids
alone [3–5]. However, the adoption rate of FM systems by
this population is low, possibly due to cost, esthetics, or
lack of counseling [3, 5].
FM systems can also benefit adults using cochlear im-
plants (CI) resulting in significant improvements in speech
perception in noise and improvements in sound clarity,
ease of listening, and sound quality [6, 7]. Fitzpatrick et al.
 conducted a purely subjective evaluation, designed to
document FM use in everyday situations in a diary, and
showed that CI users do perceive that they benefit from the
FM when at a distance from the speaker or in noise.
Nonetheless, the physical size of the device and the com-
plexity of connecting it to the CI did deter some subjects
from using the FM, even when they recognized that some
speech perception improvement could be gained.
Fixed gain FM receivers apply one gain value to all
incoming signals, typically ?10. Dynamic gain offers the
ability for this parameter to be altered automatically, de-
pending on the speech and noise content of the input signal.
In the Phonak MLxi receiver (Phonak AG, Switzerland), a
low gain of ?10 is used when the ambient noise level is
below 57 dB SPL increasing to ?24 at a noise level of
75 dB SPL. In a study of two groups of CI users using the
Phonak inspiro FM Transmitter and the MLxi (adaptive) or
MLxS (fixed) FM receivers, Wolfe et al.  found that the
Dynamic FM resulted in significantly better performance
for sentences in noise compared to the traditional FM.
Significant improvements in sentences in noise were also
observed for Dynamic FM when used in combination with
hearing aids at higher noise levels .
A further study by Wolfe et al.  looked at the latest
technology in this area—digital transmission of the signal
between the transmitter and receiver. This system no longer
uses frequency modulation, and therefore technically
speaking can no longer be referred to as an FM system. The
Phonak Roger system (Mü lder, Roger: The new wireless
technology standard, Phonak Insight 2013) features an
adaptive gain adjustment similar to the Phonak MLxi
system, but using a digital signal transmission and digital
signal processing to manipulate the gain increases. This
system was compared to the MLxS fixed gain receiver as
well as to the MLxi in a classroom-like setup with a single
talker . Subjects were16 CI recipients fitted with an
Advanced Bionics Harmony speech processor and 21 re-
cipients fitted with a Cochlear CP810 processor. The
Phonak inspiro transmitter was used, and the FM receivers
were coupled to the CI speech processors using the iCon-
nect FM earhook and the Europlug adaptor, respectively.
Speech perception results were significantly better in all the
FM conditions compared to the no-FM conditions. At the
highest noise levels, the Roger system provided sig-
nificantly better speech perception compared to either the
fixed gain MLxS or the adaptive gain MLxi receivers. This
additional advantage over the analog adaptive gain system
may be due to the wider bandwidth provided by the digital
system or to the clearer signal transmission. The authors
note that the results of the study can only be applied to the
Harmony and CP810 processors, although a similar study
also showed that the Roger system was superior to the
MLxi and MLxS at the higher noise levels with a MED-EL
Opus2 speech processor .
The Naı́da CI Q70 speech processor is the latest in
speech processor technology offered by Advanced Bionics.
Recent results reported by Wolfe  demonstrate that
Roger provides significant benefit for understanding speech
in high levels of noise when used with the integrated Roger
17 receiver on the Naida CI Q70 in a simulated classroom
environment with a single talker.
The primary objective of this study was to determine the
speech perception advantage gained in noise with the
Roger Pen transmitter and the Naı́da CI Q70 speech pro-
cessor with integrated Roger 17 receiver. While most
previous research with FM systems has focused on the
classroom situation with a single talker, the present study
was setup to test the Roger system in a group conversation
situation, in a simulated restaurant environment with
multiple talkers. In this situation, multiple Roger Pens, one
for each talker, can be used in a network configuration
where more than one microphone are able to transmit to the
receiver individually. To compare with a fair alternative,
subjects were also evaluated in the same configuration with
just one Roger Pen lying in the middle of the table. This
single-transmitter situation would currently be the typical
way a user would take advantage of the Roger Pen or any
alternative wireless microphone system in a lively discus-
sion with multiple speakers.
Twelve adults participated in this randomized, prospective,
within-subjects repeated measures design study. The study
was approved by the Ethical Board of Jessa Hospital
(Hasselt, Belgium) on August 5th 2014, under the reference
Eur Arch Otorhinolaryngol
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