jwilzewske: audiometry

Showing posts with label audiometry. Show all posts

Sunday, March 13, 2011

Meditating on Ken Ueno, Musical Seismology, Japan

U eno’s concert music, writing for a variety of ensembles from chamber groups to orchestra, has been informed in significant ways by his experiences as a performer... Cultural resonances abound in his music; for example, the biwa and shakahuachi concerto Kaze-no-Oka (‘Hill of the Winds’) has an architectural basis, being inspired by buildings designed by Fumihiko Maki... [Japanese] ideograms are used as musical formants, the details of which can be extrapolated and recontexualized to create an organic, but continually changing, whole. Subjecting an acoustical object or objects to scrutiny using computer-based tools of timbral analysis, Ueno extracts details of its musical makeup, such as its prevailing frequencies and how that profile might change over time... What are the limits of perception? ... In Kaze-no-Oka, in addition to the architectural origin, the conceptual-musical idea is of the orchestral body as a reflection and amplification of the biwa (orchestral strings as ‘super-biwa’) and shakuhachi (bass sax and contrabass clarinet as ‘super-shakuhachi’).”
— Robert Kirzinger, liner notes, Ken Ueno - BMOP ‘Talus’ CD.

I was relieved to hear that composer Ken Ueno’s parents, grandma, and other family members in Japan are okay following the quake and tsunami.

T hinking of them and others affected by Friday’s magnitude 8.9 temblor and hundreds of aftershocks, I put Ken’s CD ‘Talus’ on to play. I look at its CD jewelcase. It still bears this orange warning label:

I think: how big is the dynamic range in decibels of the music in this recording, to which the safety warning label refers? The quietest room on Earth (the old Sound 80 studio in Minneapolis) has an ambient sound pressure level (SPL) of -9.4 dB. And the latent SPL of the top-of-the-line audio signal path (microphones, cables, connectors, pre-amps, amps, EQ, digital recording media, audio workstations/mixing consoles, audio CD media, playback amplifier and EQ, monitors/headphones, tympanic membranes and ossicles in the ears, cochlea, Organ of Corti, spiral ganglion, and acoustic nerve, cranial nerve VIII) is about 3.1 dB RMS, at 2 KHz and 20 years of age.

T he corresponding minimum perceptible ambient vibration in the Earth is about -0.7 Richter, according to Thouvenot and Bouchon (see link, below).

T he biggest recorded earthquake was the Great Chilean Earthquake of 22-MAY-1960, which had a magnitude of 9.5 Richter. So, 10 times [9.5 minus -0.7] equals a perceptible dynamic range of 102 dB for maximum earthshaking ever, and 96 dB for Friday’s Japanese earthquake.

A nd the approximate maximum of dynamic range for playing this BMOP CD of Ken’s is about 96 dB on standard digital audio at 16-bit resolution and 44.1 KHz sampling rate, given the limits of CDs and available amplifier chains and monitors/headphones.

K en’s ‘Talus’ CD jewelcase orange warning label alerts us to acoustic SPL differences in his compositions that are basically comparable to the SPL differences of what people experienced in Japan on Friday, just in different ranges of frequency spectrum. [...Heeding orange warning label, turns volume down.]

[30-sec clip, BMOP, Ken Ueno, ‘Kaze-no-Oka’, 1.1MB MP3]

K en’s music is like koans... not a progression from pain to realization, or pain and loss as a reminder of realization. It is the lean-ness of the mind focusing on the present, consciously exerting energy in the face of difficult odds and adversity. Yamada Roshi: “When you stand up, there is only that standing-up in the whole world, with nothing sticking to it.” Ueno’s music is, like, “This! Just this!” ... something of a ‘last word,’ a rhetoric of pure experience. His compositions’ expression is without judgment, sort of a Zen-like “letting the Shodo calligraphy brush write whatever it wants,” but that does not mean that it is ‘acquiescing’ or accepting of the reality, the suffering that Nature dishes out, nor is it free from worry.

O ur thoughts go out to those in Japan and their families.

Video #1
Video #2
Video #3

D o not say
that the deepest meaning
comes only from one’s mouth!

Day and night,
eighty thousand poems
arise one after the other—

and in fact
not one audible utterance
has ever been spoken.”
— Musō Soseki (夢窓疎石, 1275 – 1351).

Wednesday, November 14, 2007

Neuroprotective Approaches for Mitigating Hearing Injury in Chamber Musicians?

Inner Ear Hair Cells. SEM, © SPL / Photo Researchers, Inc.

What, if anything, can a chamber music performer do to restore or preserve hearing? You’re already taking care to avoid noisy environments as much as you can. You avoid playing mp3s at high volume. You wear noise-cancelling headphones when you fly or ride the train. You are careful about your nutrition. You avoid ED meds like Viagra. What else can you do?

Pharmaceuticals and nutraceuticals are no panacea. But there are a few things that have shown recent promise and may deserve consideration, either as neuroprotective preventives [before hearing loss has occurred] or as a component of a regimen aimed at helping the body to recover hearing [when a loss that has occurred is (partially) reversible].

Prescription meds (off-label usage)

minocycline (Minocin®) 100 mg
riluzole (Rilutek®) 50 mg
levetiracetam (Keppra®) 250 mg

Non-prescription dietary supplements

piracetam 800 mg
magnesium 250 mg
vitamin C 500 mg
vitamin E 400 IU

Among anti-oxidants, ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one] is not yet FDA-approved for any clinical indication. It’s being studied as a neuroprotective in Japan and elsewhere but not for hearing loss. Based on the interest in hearing loss management among CMT readers in past months, I plan to post again in the future on this topic as new information becomes available regarding this and other meds.

Besides the foregoing, you may want to consider getting audiometry testing done on an annual basis. You want serial measurements so that you will know, quantitatively and objectively, what changes are occurring and respond promptly to those trends. Audiometry should be carried out at 0.25, 0.5, 1.0, 2.0, 4.0, 6.0 and 8.0 kHz so that problems concerning lack of data at certain frequencies do not arise. Longitudinal monitoring by audiometry will enable you to assess whether the preventive or corrective measures you are taking are achieving worthwhile benefits or not.

Such testing can be something you perform yourself, if you wish—at whatever time intervals suit you. Small software-driven audiometers that automatically conduct testing are readily available and can be ordered off the web. These can be purchased for $400 to $1,000 (see links below). For an ascending sequence, the automated audiometry self-test sequence begins with the lowest sound-intensity level selected and tests at each level, up to the highest level selected, or until you press the response button after a sound presentation. Once you respond to a sound presentation that the audiometer emits in the headphones, that presentation level is recorded as the screening result. Then it changes to one of the other frequencies and executes another software-controlled sequence of sound-intensity levels for that frequency, and so on, until the entire acoustic spectrum has been sampled. For a descending test sequence, the audiometer software begins at the highest sound-intensity level selected and tests at successive levels down to the lowest level selected. Once you do not press the response button after a signal presentation, the level of the previously presented signal is recorded as the audiometric screening result. It then proceeds automatically to the next frequency to test. When all of the frequencies have been tested, the audiometer then saves the testing results and optionally prints a report or saves the report as a Microsoft Word document or an Adobe Acrobat document. It takes less than 20 minutes to do this at home. Obviously, self-monitoring is no substitute for care by a qualified otolaryngologist / neurologist. But it is an additional option that is available to you with relatively inexpensive, simple, portable equipment today. (After all, you spend quite a bit on your iPod, on your laptop, on other technology ... Why wouldn't you spend several hundred on an audiometer, if you’re a musician?)

Okay. So much for what you can do as an individual. What about collective measures? It’s certainly impossible to ask your fellow ensemble members to play more quietly (the equivalent of reducing noise levels in industry). However, it is possible that careful planning of ensembles’ repertoires and the sequence in which pieces are rehearsed might be a general solution to reducing sound level exposures or reducing the ‘duty-cycle’ of high-volume, high sound-pressure intervals.

Apropos of those chamber musicians whose main job is in a symphony orchestra, you should know that some orchestras use screens placed around musicians who play ‘loud’ instruments (brass; percussion) to shield other players from the excessive sound intensity. Of course, the musician playing the high-volume instrument is still exposed. Rarely, the layout of orchestras has also been altered in some cases, by using raised sections in an attempt to reduce local sound levels. Maybe this could be done more often and more deliberately, for the good of all.

Individual use of hearing protection in the form of noise-cancelling headphones and studio audio feeds to all of the players is a possibility, especially now that noise-cancelling headphones are readily available which have good dynamic range and modest sound attenuation. However, in the case of clarinet players, the use of these is not an option, as bone conduction carries the vibrations from the reed, via the upper teeth to the inner ear. Noise-cancelling headphones would interfere with ordinary performance for clarinet and other wind instruments. Totally unworkable.

Chamber Orchestra of Philadelphia, Recording Session, members with headphones on.

M ost musicians don’t have a clue about this. They start playing music in fourth or fifth grade and nobody mentions the damage they might be causing themselves. A musician who can’t hear is like a painter who can’t see or a sculptor who can’t feel. Not being able to hear the nuances in the music he/she plays – the upper harmonics, the colors. I just don’t have the same confidence I used to. I don’t have the same control. That’s the most frustrating part to me.”
— Kris Chesky, Trumpet, and Research Assistant Professor, University of North Texas Center for Music and Medicine

Inner Ear Hair Cells. SEM, © G. Brederg / Photo Researchers, Inc.

CMT should not be considered as medical advice, and the remarks in these blog posts are not a substitute for professional medical advice, diagnosis, or treatment. Never delay or disregard seeking professional medical advice from your physician, pharmacist, or other qualified healthcare provider because of something you have read on CMT. You should always speak with your doctor before you start, stop, or change any prescribed part of your care plan or treatment. CMT understands that reading individual, real-life experiences may be a helpful health information resource but they are never a substitute for professional medical advice from a qualified healthcare provider.