Everything about hearing in GURPS

Everything about hearing in GURPS

Remember my post about vision? Let's compile all the data about hearing in GURPS. This is probably going to be another long, detailed post, but less so than the one about vision.

Let's start with the basics. Hearing, just like all other senses, is based on your Perception secondary characteristic, which in turn is based on IQ. GUPRS Power-Ups 9: Alternate Attributes has alternative options, such as basing Perception on DX, HT, HT+IQ, or making it independent.  There's also an option of decoupling senses from Perception, resulting in Hearing being at attribute of its own.

Sense rolls, including Hearing rolls, are described on page 358 of GURPS Basic Set. A successful Sense roll is needed to notice something, but in some cases a follow-up IQ or skill roll is required to understand what you have sensed. In case of Hearing, a Hearing roll is made when it is important whether you can hear something or not, and a follow-up IQ roll is often required to make out speech, especially in a foreign language. Your roll is modifier by certain advantages and disadvantages, and by the local circumstances, such as background noise and the loudness of the sounds you are trying to hear.

Hearing rolls take range penalties but in a weird way that doesn't mesh with the rest of GURPS well. This sense does not use the normal speed/range penalty table, nor the long-distance modifiers, but instead uses its own table. Basically, the table consists of range steps that are equal to powers of 2. Each sound is assigned to a step, and the distance for this step indicates the range at which the Hearing roll to hear this sound takes no penalty. Each step of difference determines the penalty or bonus you get to your Hearing roll. In other words, each doubling of the unpenalized Hearing roll distance imposes a -1 penalty to Hearing, and each halving grants a +1 bonus. If I were designing this table, I would include things such as footsteps, swordfight, and gunshots on this table instead of various rock concerts.

When you try to hear someone who is attempting to move silently, the GM may treat this roll as a Quick Contest against his Stealth skill. If you are actively listening for such activity, the GM may allow you to substitute Observation skill for Hearing. How do these Quick Contests interact with distance? I have no idea. I strongly suggest using this variant Stealth system.

GURPS Powers: Enhanced Senses classifies Hearing as a scanning sense in terms of range, 360° Sense in terms of arc, and a basic sense in terms of sensory hierarchy. This means that you know the direction to the sound source when you make a successful Hearing roll, but you cannot use it for imaging, navigation, or targeting. Hearing is a passive sense. The same book provides a way to apply various limitations or enhancment to normal hearing, pricing them as 1/10 the percentage value of the modifier.

Now let's go over all the disadvantages related to hearing.

    Deafness prevents you from hearing anything. However, it comes with a slight upside that I didn't know about prior to writing this post - all time you spend communicating this way counts at full value for study of the skills used (Gesture, Lip Reading, etc.) Deaf characters also do not take positive or negative reaction modifiers from such traits as Voice, Disturbing Voice, or Stuttering. Deafness also makes you immune to hearing-based abilities.

    Hard of Hearing represents a partial hearing loss, penalizing your Hearing and Hearing-based rolls by 4. This disadvantage also gives you a bonus to resist hearing-based abilities.

    Noisy is somewhat hearing-related, making you easier to hear.

    Phantom Voices creates voices that only you can hear, but it's not really hearing-related.

    Brontophobia is the fear of loud noises.

    GURPS Power-Ups 6: Quirks also has some hearing-related quirks.

    Loud Voice makes it easier to hear you talk.

    High-Frequency Hearing Loss and Low-Frequency Hearing Loss impose penalties to hear some high-frequency and low-frequency sounds.

    Tone-Deaf penalizes your musical abilities.

There's also some advantages that are, or can be related to hearing.

    Acute Hearing simply improves your Hearing rolls.

    Affliction, Innate Attack, and other advantages can be made reliant on hearing by applying the Hearing-Based modifier. Alternatively, you may want to able to affect only those who you can hear with your unaided hearing by applying Hearing-Based, Reversed. And you can also afflict Deafness or other hearing-related traits. Note that if your ability relies on sound and not only on hearing, then you might want to add either Environmental, Air/Water, -5% or Environmental, Sound-transmitting mediums, -10%. The latter differs from the former in that it is blocked by Silence, Wall of Silence, and similar effects.

    Clairsentience can displace your sense of hearing with the Clairaudience limitation.

    Discriminatory Hearing moves hearing one step up the sensory hierarchy, allowing you to identify sound sources by listening to them and providing you with a +4 bonus to Hearing. This ability can also imitate submarine passive sonar, apparently.

    Invisibility has a variant that makes you invisible to sonar. I believe that it should also make you inaudible, but the advantage does not specify that.

    Mimicry lets you imitate any sound you can hear.

    Obscure can be used to obscure hearing. It only affects normal hearing by default, with the possibilities to extend the frequency spectrum with enchantments. Without Stealthy, +100%, the borders of the effect will be much easier to detect. Also, Pyramid #3-99 has additional modifiers to make Obscure only affect combat rolls, or make them provide a bonus to Hearing rolls.

    Parabolic Hearing seems like it provides the same benefit as Acute Hearing but at double the cost. But that's not exactly true, as it also lets you filter out background noise. This is described in more detail in a Krommpost.

    Penetrating Vision has a hearing-based variant in GURPS Sorcery: Sound Spells. Feels weird mentioning something I came up with myself.

    Protected Hearing gives you a bonus to resist hearing-based attacks.

    Rapier Wit, an advantage that I do not like at all, is hearing-reliant.

    See Invisible doesn't have a hearing-based variant, now that I look at it, especially after mentioning the sonar Invisibility. But why not? I think a Hear Inaudible advantage should be absolutely fine.

    Sonar is a Scanning Sense variant that is hearing-related.

    Silence is a trait that makes you harder to hear.

    Subsonic Hearing lets you hear very low-frequency sounds. Optionally, may be taken as a feature to let you only hear those sounds.

    Subsonic Speech includes the aforementioned Subsonic Hearing. Speaking in this range is slower, but it carries twice as far. Can be taken as an advantage, if you can speak both normally and in the subsonic range, or as a feature, if you can only speak in the subsonic range.

    Terror has a hearing-based variant by default.

    Ultrahearing lets you hear very high-frequency sounds, such as motion detectors and sonars. Optionally, may be taken as a feature to let you only hear those sounds.

    Ultrasonic Speech includes the aforementioned Ultrahearing. Can be taken as an advantage, if you can speak both normally and in the ultrasonic range, or as a feature, if you can only speak in the ultrasonic range.

    Vibration Sense is often considered to be related to hearing, even be GURPS Powers: Enhanced Senses. I also have to say that I usually represent the D&D tremorsense as Vibration Sense with Environmental, Ground, -20%.

    Voice makes your voice more pleasant to hear.

    GURPS Powers also has Illusion (p. P94) that can fool auditory senses. By default it only fools normal hearing, but additional modifiers can extend the frequency.

    There's also some hearing-related perks.

    Penetrating Voice lets you yell very loudly.

    Extended Hearing lets you barely hear either ultrasonic or subsonic frequencies in silent environments.

    Robust Hearing provides a bonus to resist hearing-based abilities.

    Perfect Pitch makes you better at tuning musical instruments.

    Injury Tolerance (No Ears) removes your optional ear hit location.

HEARING AND ACTIONS

Most importantly, Hearing can be used to fight invisible opponents as per the Visibility rules from p. B394.

    GURPS Powers: Enhanced Senses has a few example abilities based on applying modifiers to normal hearing, resulting in Precise Hearing that lets you determine the distance to the source of sound, and Targeting Hearing that makes it easier to aim using hearing. Definitely check out that book.

    Page 21 of GURPS Powers: Enhanced Senses has an extended version of the hearing chart, including such sounds as silenced pistol shots, normal pistol shots, and the actual noise levels for various results of a Stealth roll! This is a lifesaver.

    Page 22 also has rules on hearing in tunnels. Slightly expanded rules on hearing in tunnels are presented on page 10 of GURPS Underground Adventures. Hearing also works differently underwater - consult page 7 of Pyramid #3-26.

    Explosive decompression due to vacuum (p. B437) can damage your hearing.

    GURPS Martial Arts has the Ear Clap technique that can temporarily or permanently deafen the victim. On pages 137-139 it also has rules for the optional Ear hit location and the possibility of hearing loss on a major skull wound.

SKILLS

Now let's go over the skills that are related to vision.

    Blind Fighting (p. B180) is a cinematic skill that allows you to fight blindly (or fight invisible enemies) more effectively by relying on hearing or other senses. It is penalized by background noise, and gets a bonus from Acute Hearing.

    All Enthrallment (p. B191) skills are cinematic and/or supernatural skills that rely on hearing. Typical skills for bards.

    Group Performance (Conducting) (p. B198) is not penalized by Deafness or Hard of Hearing. But it probably should!

    Hypnotism (p. B201) may be reliant on hearing, depending on how it works in your setting.

    Kiai (p. B203) is not reliant on hearing, but Hard of Hearing and Deafness still provide a bonus to resist it.

    Mimicry (p. B210) can be used to fool the sense of hearing.

    Musical Composition (p. B210) is not penalized for Deafness or Hard of Hearing, but we do know a particular deaf composer, right?

    Musical Influence (p. B210) is another bardic cinematic/supernatural skill that is reliant on hearing. Hard of Hearing provides a bonus to resist, and Deafness makes the subject immune.

    Musical Instrument (p. B211) is not penalized for Deafness or Hard of Hearing. Should it? I don't know.

    Observation (p. B211) can replace Hearing when being on the lookout for noisy intruders, as was mentioned at the start of the post.

    Shadowing (p. B219) gets a bonus from Discriminatory Hearing.

    Singing (p. B220) is not penalized for Deafness or Hard of Hearing. Should it? I don't know.

    Stealth (p. B222), of course, is used to sneak past somebody unheard.

    Tracking (p. B226) gets a bonus from Subsonic Hearing if the quarry is running on the ground.

    Ventriloquism (p. B228) can be used to fool the sense of hearing.