The Lion Roar is the Voice and Sound of Africa

 

Old male lion

Off in the distance in the savannahs of Africa, you listen, and a roar comes out of the deep, creating an uneasy trepidation.  The lion’s roar is indeed the voice and sound of Africa.  It sends an awesome message to the world that he is lord and master to all he surveys.

For a human observer, the roaring of a lion – even more so that of a whole pride – is one of the most impressive vocalizations in the animal kingdom.  The author videoed multiple lion experiences in the Mala Mala and Sabi Sands areas of Mpumalanga, South Africa.  The following was a rather “interesting” experience with lions at close range one evening when stuck in the Sabi River bed in Mala Mala South Africa, with a pride of 17 lions surrounding the vehicle.  The roars are about 2/3rd through this first video. Fortunately, the lion pride had already eaten for the evening.

Unlike most large cats, lions are very social animals that live in prides.  A pride can be composed of up to thirty lions, although most are smaller.  The pride contains one or more males, who are often brothers, and related adult females and their cubs.  Each pride has its own hierarchial system, with one dominant male as the master of the pride and territory.  The weaker males rank above all females.  Both males and females hunt for the pride and help defend against predators.

Lions relaxing and blocking our path during a game drive.

However, living in such close contact requires that lions have very effective communication to live together successfully.  This level of communication is greater for lions than for other large cats (leopards, cheetahs), which are more antisocial than lions.  As a result, lions produce a greater variety of sounds.  Still, the language of most cats is less developed and complicated than that of other animals.

For lions, daytime is for resting.

Lions are social animals, so after all that sleeping and relaxation (up to 20 hours a day), hunting and eating, the other important aspect of the lion’s life is communicating.

Lions communicate with one another through a variety of methods, including body language, appearance, behavior, touch, scent, and vocalization.

  1. Social order.  Dominant males are most apt to let a pride member know when he or she is out of order.  This is often done with a quick swat of the paw or a gentle bite to the neck.  They also communicate by example, as in a staged hunt where cubs are shown how the hunt is done.  And, lions also show affection in their own special way when relaxing by licking gently or gnawing at each other.
  2. Appearance.  The impressive mane of the male gives the appearance of a large head, and therefore the impression of a significant threat.  The male’s size and attitude of eerie calm are often sufficient to let any upstarts know to back off.  But, this is not their only signaling tool.  The large teeth of the lion are certainly functional, but they also serve to let others know just how powerful their bite can be.  Baring teeth essentially says “don’t mess with me.”
  3. Behavior.  Lions also communicate with lions from outside the pride that attempt to compete with them for resources or territory.  They use urine to delineate the borders of their territory; the scent warns others that crossing the line means certain conflict.  Lions also form coalitions, often made up of male relatives, to patrol the claimed areas.  They stand at the borders and stare down those who have ventured too close for comfort.  If staring isn’t enough to scare off the intruders, a lion will let out a powerful roar.  This signals that the lion means business – an indication of his strength and intention to fight.
  4. Touch.  Lions from the same pride greet each other by rubbing their cheeks, necks, and bodies together.  Grooming each other helps the pride bond with each other.  Their hard bumpy tongues are used to comb each other’s fur and remove ticks.  When lions are relaxing they show affection by licking gently or gnawing at each other.
  5. Scent.  Lions have many scent glands on their cheeks, lips, forehead, chin, tail, and even between their toes.  Scent communicates with other lions where they have been and how long ago.  Scent is also used to attract a mate.  They can smell other cats using an extra smell organ called the Jacobson’s organ.  To use this organ, the lion shuts off its nose, curls its upper lip, and sucks air through its mouth.  Males also leave a calling card in the area [1] consisting of a scent mixed with urine on bushes and turfs of grass (Animal Behavior p72). This signals to any nomadic lion that he is in another lion’s territory.
  6. Posturing.  Lions use many parts of their bodies to communicate their feelings, with the most important part being their face.  When they feel threatened and scared, they show their weapons (claws and teeth), stand on their tiptoes, raise their tails, and hunch their backs in an attempt to look at large as possible.  The dominant male will walk with his head held high, ears standing upright, mouth closed, and tail swishing side-to-side.  The more submissive members of the pride walk with their heads held low, eyes flattened against their heads, mouths open, and teeth showing.  It is said that lions are able to detect event the slightest change in posture of another lion.
  7. Vocalizations.  Lions communicate with different noises, such as ferocious roars to call another lion or a soft rumble to indicate their satisfaction. [2]

The Roar of the Lion

Female lion and cub.

In the pride, both sexes roar to broadcast ownership and defense of a territory, or under some circumstances, to attract mates. [1] Male lions roar to advertise their territory to other lions, whereas female lions roar to maintain contact with other lionesses, protection, or location.

Lionesses can also estimate the number of individuals roaring, and are less likely to approach foreign roars when they are outnumbered. [3]  A second video shows the result of a male lion in a tree, having taken a leopard’s impala kill, dropping to the ground, and stopping a very short distance from us to eat the remains of the carcass.  Listen to the sounds of the feast.

 

An additional function might also be coordination of hunting where they can communicate differently other than with a roar.  On the hunt a lioness lashes her tail, but just before the final attack,  holds it straight out behind. To the lioness the roar means protection or just “Here I am.”  If enemies approach a lioness, she will give off warning signals such as flattering her eyelids and lashing her tail.  Females and their cubs use the largest variety of calls to communicate because they are the members of the pride that spend the most time together.

Nomadic males wander widely, passing through pride ranges single or in coalitions until they are successful in taking over a pride of their own [4] [5]   Roaring provides a means by which nomadic males might co-ordinate their movements with coalition partners or to recruit new ones.[3] [6]

However, if nomads used this loud long-distance signal to communicate with social companions they would also advertise their position to resident males in the area.  The costs to nomadic males on engaging the attention of resident males may be considerable.  Resident male lions consistently give aggressive approaches to roaring from strange males broadcast in their territories.  Observations indicate that real intercoalition encounters may be fatal.  Interestingly, nomad lions without a pride are unlikely to roar in another lion’s territory unless a challenge to the pride control is being made.

Female lions listening and preparing for the night hunt. Mala Mala, Mpulalamba South Africa.

Roar Described

Roars are loud, low-pitched vocalizations that are delivered in bouts, which typically last 30 to 60 seconds and consist of several soft introductory maons, a series of full-throated roars and a terminating sequence of grunts. [3] [6] Lions are active primarily at night, and most roaring occurs during nocturnal hours [1] [4].

 

 

 

 

To be even more specific, lion roaring has two distinct physiological and acoustic components:

  1. A low fundamental frequency, made possible by long or heavy vocal folds, which lead to the low pitch of the roar;
  2. Lowered formant frequencies, made possible by an elongated vocal tract, which provide the impressive baritone timbre of roars.  [7]

Lion eating impala kill taken from a leopard.

The lion is the loudest of all the big cats with their roar reaching up to 114 dB SPL at 1 meter.*  Because they are one of the most threatening predators in the wild, they are not concerned about being too noisy.  Lions are active primarily at night, and most roaring occurs during nocturnal hours.

Spectrographic analysis of lion roar reveals both low-frequency components with a fundamental frequency around 180-194 Hz and a higher-frequency component around 4,000 Hz.  A gender difference also exists with the fundamental frequency for males at about 195 Hz and for females about 207 Hz. [8]  The roar can be heard at least 5 miles (8 km). [9]

Young lions – Mala Mala, South Africa

The lion roar is a series of calls with a fairly regular structure consisting of a single call followed by a series.  The series, however, changes in call type, intensity, temporal sequencing, duration, and intervals between them.  A typical lion roaring can last for more than a minute, usually starting with a few low-intensity moan-like calls, then progressively increasing in intensity and duration, and upon approaching the intensity climax the calls become shorter again and harsher.  Following the climax is a series of short harsh calls, in the beginning uttered at fairly monotonic intensity and brief intervals between the calls, then towards the end of the series gradually decreasing in intensity and with increasing interval duration.

A third video shows a pride of lions on an impala kill at night.  Listen to the sounds of the pride while dining.

 

*I have added the SPL identifier to the sound level because the reference did not list it as such.  However, this seems like a reasonable assumption because sound level meters seem to have been the measurement tool used.

(A coming blog on “The Sounds of Africa” will feature the leopard and rhino – two more of the Africa Big 5)

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Footnotes    (↵ returns to text)

  1. Schaller, G. B. 1972. The Serengeti Lion. Chicago: University of Chicago Press
  2. Lynn, R.  Life in the pride.  Disney Adventures, July 30, 1994, p29-31
  3. Schaller, G. B. 1972. The Serengeti Lion. Chicago: University of Chicago Press
  4. McComb, K., Packer, C. & Pusey, A. 1994.  Roaring and numerical assessment in contests between groups of female lions, Panthera leo. Animal Behaviour, 47, 379387
  5. Hanby, J. P. & Bygott, J. D. 1987. Why do subadult lions leave their natal pride? Animal Behaviour, 35, 161169
  6. Pusey, A. E. & Packer, C. 1987. The evolution of sex-biased dispersal in lions. Behaviour, 101, 275310
  7. McComb, K., Packer, C. & Pusey, A. 1994. Roaring and numerical assessment in contests between groups of female lions, Panthera leo. Animal Behaviour, 47, 379387
  8. Grinnell, J., Packer, C. & Pusey, A. E. 1995. Cooperation in male lions: kinship, reciprocity or mutualism? Animal Behaviour, 49, 95105
  9. McComb, K., Packer, C. & Pusey, A. 1994. Roaring and numerical assessment in contests between groups of female lions, Panthera leo. Animal Behaviour, 47, 379387
  10. Grinnell, J., Packer, C. & Pusey, A. E. 1995. Cooperation in male lions: kinship, reciprocity or mutualism? Animal Behaviour, 49, 95105
  11. Schaller, G. B. 1972. The Serengeti Lion. Chicago: University of Chicago Press
  12. Hanby, J. P. & Bygott, J. D. 1987. Why do subadult lions leave their natal pride?  Animal Behaviour, 35, 161169
  13. Weissengruber, G. E., Forstenpointer, G., Peters, G., Kubber-Heiss, A. and Fitch, W. T. (2002). Hyoid apparatus and pharynx in the lion (Pantera leo), jaguar (Panthera onca), tiger (Pantera tigris), cheetah (Acinonyx jubatus), and domestic cat (Felis silvestris f. catus). J. Anat. 201, 195-209
  14. Eklund, R., Peters, G., and Mabiza, E.  An acoustic analysis of lion roars. II: vocal tract characteristics.  2011, TMH-QPSR Vol. 51, p 5-8
  15. Sunquist, M. and Sunquist, F. Wild Cats of the World. 2002.  University of Chicago Press, 462 pages
 
 

Self-Fitting of Hearing Devices – Part I

 

Self-fitting of hearing devices is an inherent feature of OTC or DTC (over-the-counter; direct-to-consumer) hearing aids.  What can we expect now that this is becoming an active feature of hearing aid sales?

The real issue, as expressed by Bess1, is not how an OTC or DTC hearing aid delivery system benefits hearing aid manufacturers and hearing professionals, but will this benefit those with hearing loss?  The OTC option is intended to provide greater access for individuals to use amplification than does the current model of hearing aid distribution.  Without a doubt, the current distribution system would not be able to manage the influx of sales if the intended goal is to substantially increase the number of individuals using amplification.2   With this in mind, some have been concerned that OTC (over-the-counter) sales, which essentially includes self-fitting of hearing aids, cannot be managed effectively by the consumer.

 

Self-Fitting Defined

What is a self-fitted hearing device?

The essence of self-fitting is that the assembly, fitting and usage of hearing aids is completed by the user without any hearing experts and equipment, other than the hearing aid.

In this series of posts that will follow, as related to OTC sales, PSAPs (Personal Sound Amplification Products) are considered to be the same as OTC hearing aids, which they are, regardless of how some chose to nit-pick definitions.

The definition above of self-fitting is different than what some have suggested, such as:

“A self-contained, self-fitting hearing aid (SFHA) is a device that enables the user to perform both threshold measurements leading to a prescribed hearing aid setting and fine-tuning, without the need for audiological support or access to other equipment.”3

This author prefers the initial definition of self-fitting and has problems with this latter definition, and for other similar definitions that suggest the need for audiometric data for a self-fitted device, for the following reasons:

  • There is no need to have a measurement of one’s hearing thresholds. This has been explained in a previous post.  For the most part, there is little difference in the threshold configuration of most mild and moderate hearing losses, other than the sensitivity level and minor changes in the high-end response, much of which can be managed easily with a user-adjustable volume control, and a couple of push-button response changes, if that is even desired.
  • The FIRST, and PRIMARY decision that all hearing aid users make is if the instrument has sufficient gain. Is it proving enough amplification so that they can hear others/things better than without amplification, and to their satisfaction.  Knowing this, give the customers a user-controlled gain option.  After all, they can make a better decision as to what gain they will accept than can an external evaluator or fitting formula.4,5   As to the significance of frequency response adjustment, few users can tell the difference in frequency response unless it is dramatic – more dramatic than the environmental differences often programmed into hearing aids today.  Anecdotal evidence can easily be obtained by asking customers if they can tell the difference between the various environmental settings.  To most, they sound the same, with the exception of a loudness reduction when the directional microphone performance is chosen (generally, listening in noise).
  • To use hearing thresholds to lead to a prescribed hearing aid setting is no guarantee of a successful hearing aid fitting because of the great variability in target gains projected by different hearing aid formulae.6,7,8,9,10 As reported previously, Hearing instrument manufacturers’ first-fit algorithms are known to deviate significantly from actual prescriptive targets.8,10   Aazh and Moore found that using first-fit, 64% of hearing instruments failed to come within +/- 10 dB of target at one or more frequencies.  Similar results were found for open-fit hearing aids.10
  • Hearing thresholds have little or nothing to do with fine tuning of a listening device. Fine tuning is generally performed by changes to target gains based on subjective responses by the hearing aid user, not on audiometric thresholds.  Adjustments are generally made by using the program’s “Fitting Wizard” (which is a calculated guess), or best, by adjustment using real-ear measurements.  Unfortunately, few audiologists actually use real-ear measurements, even though many have the equipment in their offices.11,12,13,14,15    In a survey of dispensers, 57% reported owning real-ear equipment, but only 34% (considered an inflated percent, and perhaps closer to 25%16) of all respondents who reported that they used the equipment consistently, even though it is considered a major part of Best Practice.13    

The suggestion that a measurement of hearing threshold is required is without doubt, the single greatest artificial/intentional roadblock to self-fitting of hearing aids.   


What is Available for Self-Fitting?

An excellent review of partial self-fitting without audiological support has been published by Keidser and Convery.2  The devices identified in the reviews of that publication universally required access to other hardware, such as a proprietary interface, computer, smartphone, or tablet to enact the fitting.  None of such devices would be considered a “self-contained” or “self-fit” hearing aid by this author because they rely on some additional hardware/interface. 

Because certain approaches employ additional hardware does not make them poor options for self-fitting in and of themselves, but a true self-fit device should be something that any person can use, regardless of where in the world they live.  And, to really meet the unserved market, it should notrequire an additional device that many customers do not nor will not have access to, or perhaps cannot manage.  What if they have no cell phone service, can’t afford a computer, smart phone, or tablet?  A truly self-fitting device should require nothing more than the product itself, along with easily understood instructions on its use.

 


Are Any Such Self-Fitting Hearing Aids Available? 
 

Fortunately, current devices now exist that can be considered fully self-fitting without audiological support, assuming that one ignores the unnecessary “requirement” that an audiogram is necessary.  The Bean by Etymotic Research, the Tweak by Ear Technology, and the CS50+ by Sound World Solutions are such devices, as are essentially most PSAPs.  If any of these devices also connect wirelessly with a smart phone or with providers that offer assistance through a telehealth infrastructure or integration into a traditional hearing health-care model, that is good.  But, it is not a necessary requirement for self-fit because most (not all) of such connections are designed to obtain or use some kind of audiogram, thinking this is necessary because it has been suggested by hearing professionals.  The attempt at obtaining an audiogram is fraught with regulation and calibration issues that are best left to traditional hearing aid fitting, where it is believed that an audiogram is necessary to fit a hearing aid. 


Predicting Hearing Level Without an Audiogram

Can this be done?  It is suspected that most hearing professionals make such a prediction prior to taking an audiogram, by just talking with the customer.  It has been suggested that such a prediction could be made just using a proper questionnaire.

At least one self-assessment questionnaire has been shown to provide valuable information about an individual’s hearing levels without resorting to a pure-tone audiogram.  For example, the following comments were made relative to an inquiry made to the authors of the NSRT test, asking how well their questionnaire items related to measurements of hearing levels by category of loss.  The NSRT test was questioned because it is one of the few that has good statistical data associated with it.  The response was as follows:

“You asked how well the questionnaire items relate to the “final estimate of hearing levels by category”, as well as “general hearing level”.  Simply put, the six Likert items to which respondents provide data entries conspire very nicely to form an independent measure of hearing sensitivity (KR20 = .92).  Simple-sum scores on the questionnaire separate respondents into four HL groups (normal, mild loss, moderate loss, severe loss).  I was quite surprised to see how well respondents separate into categories based upon hearing loss (predicted PTA) simply using the questionnaire data.”17

If the purpose of a self-fit hearing aid is to get individuals who have mild-to-moderate hearing loss, and who take no amplification action because of the various hoops required of them to go through, along with unacceptable/unaffordable costs, it would appear that the drive to action should have as few obstacles as necessary.  And, the big elephant obstacle in the room relates to the audiogram.

Self-fitting of hearing aids will continue in next week’s post.

 

References

  1. Bess F. (2004).  Vanderbilt University, Fred Bess Ethics Class, November 28, 2004, Memphis, TN.
  2. Marquardt K, Hosford-Dunn H, Fishback P. (2017).  The supply and demand for audiologists: preliminary modeling and analyses.  http://hearinghealthmatters.org/journalresearchposters/files/2017/06/Supply-and-Demand-for-Audiologists-Preliminary-Modeling-and-Analyses.pdf.
  3. Keidser G. and Convery E. (2016). Self-fitting hearing aids: status quo and future predictions.  Trends in Hearing, Vol. 20, 1-15, April.
  4. Killion M. (2004). Myths about hearing aid benefit and satisfaction. The Hearing Review, August, pp 14, 16, 18-20, 66.
  5. Keidser G, Brew C, Peck A. (2003). Proprietary fitting algorithms compared with one another and with generic formulas.  Hearing Journal. 56(3):28, 32-38.
  6. Hawkins D. and Cook J. (2003). Hearing aid software predictive gain values: how accurate are they?  The Hearing Journal. July, Vol. 56, No 7, pp 26, 28, 32, 34.
  7. Aarts, N., Cafee, C. (2005). Manufacturer predicted and measured REAR values in adult hearing aid fitting: accuracy and clinical usefulness. Int. J. Audiol. 44, 293-301.
  8. Azah H. and Moore BCJ. (2007). The value of routine real ear measurement of the gain of digital hearing aids.  Journal of the American Academy of Audiology, 18(8), 653-664.
  9. Sanders, J., Stoody, T., Weber, J., Mueller, H.G., 2015. Manufacturers’ NALNL2 fittings fail real-ear verification. Rev. 21 (3), 24.
  10. Azah H, Moore BC, & Prasher D. (2012). The accuracy of matching target insertion gains with open-fit hearing aids. American Journal of Audiology, 21:175-180.
  11. Beyer C. (2011). Common mistakes in routine hearing aid fitting.  http://www.audiologyonline.com/ask-the-experts/common-mistakes-in-routine-hearing-39.
  12. Kirkwood D. (2006) Survey: Dispensers fitted more hearing aids in 2005 at higher prices. Hear J59:40–50.
  13. Bamford, J., Beresford, D., Mencher, G., 2001. Provision and fitting of new technology hearing aids: implications from a survey of some “good practice services” in UK and USA. In: Seewald, R.C., Gravel, J.S. (Eds.), A Sound Foundation through Early Amplification: Proceedings of an International Conference. Phonak AG, Stafa, Switzerland, pp. 213-219.
  14. Mueller HG, Picou EM. (2010). Survey examines popularity of real-ear probe-microphone measures. Hear Jour. 2010;63(5):27-28.
  15. Mueller HG. Probe-mic measures: Hearing aid fitting’s most neglected element. Hear Jour. 2005;57(10): 33-41.
  16. Mueller HG. 20Q: Real-ear probe-microphone measures—30 years of progress? AudiologyOnline, Article 12410 [Jan 2014].
  17. Garrison W. and Bochner J. (2017).  Personal communication in reference to the NTID (National Technical Institute for the Deaf) NSRT Speech Recognition Test.