Feature Article

Hearing Aid Issues for the Hearing Impaired Audiophile

Part III

June, 2006

Wayne Sarchett


Etymotic K-Amp CIC (from General Instrument Co.)  Non-programmable Analog.

The technology for the Etymotic K-Amp was invented and designed by Dr. Mead Killion, Founder and CEO of Etymotic Research.  He is an accomplished musician and audiophile, so it is not a surprise that this hearing aid is musical and excellent.  Etymotic is best known for their ER-4 and ER-6 earphones, as well as high fidelity and musician Earplugs.  The company is also a research lab and manufactures measuring and test equipment.  The Etymotic hearing aid circuits are built for the OEM market and can be ordered from a number of hearing aid manufacturers, with a list posted at www.etymotic.com.

Unfortunately, this line of hearing aids is being phased out, and they are difficult to obtain.  Mine were obtained through General Instrument Co. and were the non-programmable circuit version, which was not an ideal match for my audiogram.  Had I been able to audition a programmable analog version of the K-Amp, my evaluation might have been closer to the ReSound CC4, since they are both accurate reproducers of sound.  This hearing aid did not add spurious artifacts to the sound.

Bernafone Audioflex AF 400  Programmable Analog
Phonak PiCS2 Microzoom P2 AZ  Programmable Analog

Both of these hearing aids were musical, but disappointing from an audiophile perspective, however better than the all-digital models.  These hearing aids were unable to render a palpable presence to the music or sense of recording space (soundstage).  Resolution was very poor.  The listening experience was boring and dull.  They are a very distant second to the ReSound CC4 and Etymotic K-Amp in terms of reproducing a musical event.  They had compressed dynamics, both macro and micro, poorer clarity, softened transients and just okay rhythm and pace.  They did better on small groups and solo piano than large orchestral pieces.  There was some congestion and smearing on large orchestral compositions.  Highs on the Bernafone Audioflex were bright and steely.  Bass was rolled off on both and the sound was lean and thin.  The Phonak PiCS2 suffered from serious feedback problems.

ReSound Metrix ITC all-digital (using ReSound's music program settings)

ReSound engineers have made a substantial improvement on the Metrix over the Canta 7, the previous top of the line.  The typical sonic signature of all-digital was less prevalent with the Metrix than all the other all-digital HAs.  Complex musical passages were rendered with good reproduction most of the music was there most of the time.  Rhythm and pace were good to very good.  Harmonics were very good the music was richer and fuller with the Metrix, however, in some instances I detected a slight bloomy quality. 

The volume on the Metrix is controlled by a clunky, primitive volume wheel option, which is awkward, very difficult to use, ineffective, and obsolete. My first hearing aids had them in 1974, and it was a godsend when ReSound came out with the programmable remote in 1989 with the capability of fixed incremental volume adjustments.  If one buys HAs with the volume wheel control option, expect to spend a lot of time fiddling with the wheel to get the right volume in each ear, not too much or too little and balanced, which is nearly impossible.  The first time you move the wheel, you lose track of neutral, and the only way to get it back is to reboot the program.  When adjusting, one generally overshoots and it's too loud, so then turn it down, then it's too soft, then one ear is louder or softer, so adjust again, and again, and again, etc. 

Etymotic Digi-K CIC all-digital (from General Instrument Co.) (using music program settings)

The Digi-K is musical, however unacceptable from an audiophile perspective, ranking between the ReSound Metrix and the Phonak Savia.  Its character is different from both, but in my perspective, closer to the Savia than the Metrix, in terms of musicality and sound quality.

Phonak Savia CIC all-digital (using Phonak music program settings)

The Savia is the top of the line hearing aid for Phonak and a huge improvement over the Perseo 11 in which the sound was so poor it could not be seriously evaluated.  The design and ergonomics of the Savia hearing system is exceptional.  I liked the comfort, convenience and ease of use,. Ergonomics were superb, with Bluetooth volume and program control with a remote.  The Savia reproduced most of the music, and it was in pitch. However, the ReSound CC4 sounded significantly better.  Differences between the Savia and CC4 were easily discerned.  Dynamic range was severely compressed.  All musical passages were smeared, and the presentation very muted and distant sounding there was little excitement or emotion.

Prokofieff: Lieutenant Kiji; Stravinsky: Song of the Nightingale, Reiner, Chicago Symphony; Classic/RCA LSC-2150, 180 gr. vinyl

Etymotic K-Amp CIC (from General Instrument Co.)

The sound was somewhat on the "dark side" tonal balance was tilted toward and emphasized the lower midrange and highs.  This is because these K-Amp hearing aids are non-programmable and can't be adjusted to compensate for my particular hearing loss, which needs more gain in the upper midrange to high frequencies.  This is a significant shortcoming for my hearing needs.  (At the time these were ordered my audiologist was unable to locate the programmable K-Amp for auditioning.)  With the K-Amp there was a slight suckout in the midrange to upper midrange (I heard this in voices also, especially female, which sounded a bit masculine) because they could not be matched perfectly to my hearing loss.

Transient attack on notes seemed a bit slower than the ReSound CC4s also a bit softer and less assertive, but not by very much.  K-amp was more reticent in attack and dynamics, but richer in harmonics.  Sound was glorious!

Excellent macro and micro dynamics handles complexity extremely well.  Very little, if any, congestion on loud complex passages.  Distortion was very low.  Low-level detail was excellent.  Excellent timbre (except for the darkness due to non-programmability).

The Royal Ballet, LDS-6065, Classic Records, The Nutcracker Suite, 180-gram vinyl

ReSound Metrix ITC all-digital

Overall presentation was slightly subdued/muted, and the dynamic range was compressed compared with the ReSound CC4 (and Etymotic K-Amp).  Bass drum whacks sounded muted.  The bells were very muted and distant, almost inaudible this was a major solo brilliance was lacking, timbre was poor, however single bell notes scattered throughout the composition sounded much better.  The piccolo solo was muted, a matter of poor balance with the orchestra.

I noted some smearing of notes and musical passages.  Transient attack on notes was undefined and the decay was off.  Transient attack of notes on the harp solo had a sameness quality and the timbre was also slightly off (however, this was very subtle), and totally lacking in micro dynamics and resolution. 

Transient attack was cleaner, more alive, brilliant, more fluid and assertive with the CC4; decay more realistically rendered.  Transients delivered with more speed.  Also micro dynamics were much better with CC4, giving the music more nuance, emotion and expression, and it was not subtle.

The accompaniment/background instruments were smeared more than the solo/primary/lead passages transient attack of background was not clean and crisp and the detail was muddy and undefined.

The Sleeping Beauty and Les Sylphides

Foreground, lead and theme instruments/groups were better defined, more detailed with better resolution than background/accompaniment, which sounded somewhat muddy and congealed; also separation and air between notes and instrument groups was better on the lead/theme.  There was some loss of timbre on background instruments. 

Transients were slow, with some smearing and overhang, particularly noticeable on the tympani, and the gong strike was less shimmery in its decay compared to the CC4.  The violins, with the Metrix, were dull sounding, with less life and vibrancy.  There was a loss of detail on low volume passages. 

There was a complete loss of the sense of the performing space, no hall sound, and no soundstage.

Phonak Savia CIC all-digital

Transient attack was fuzzy and undefined.  Low-level detail on soft passages was very poor.  The music was dull and lifeless.  Macro and micro dynamics were very poor the music lacked rhythm and pace.  The bells were very poorly rendered.  There was a loss of brilliance, definition, and resolution in the highs/treble notes.  Sections of the orchestra congeal together there was little to no separation or air between notes or sections of the orchestra.

There was a complete loss of the sense of the performing space, no hall sound, and no soundstage.

Click Here to Go to Part IV.

Copyright 2006 Secrets of Home Theater & High Fidelity

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