Voice warning system

Bitching Betty is the slang term some pilots and crew (mainly North American) use when referring to the voice warnings used by some aircraft systems.

The name "Betty" is a generic popular traditional name from the American culture, and is not derived from more recent uses of the word to describe an attractive female (in reference to Betty Rubble of The Flintstones).

Today, at least in some aircraft systems, the annuciation voice may be either male or female. In some cases, this may be selected according to pilot preference. If the voice is female it may be referred to as Bitching Betty; if the voice is male it may be referred to as Bitching Bob.

In the UK the term Nagging Norah is sometimes used.

Notable examples

There are two notable systems which today are normally found in most commercial and military aircraft, the TCAS (Traffic Collision Avoidance System) and TAWS/EGPWS (Terrain Avoidance Warning System / Enhanced Ground Proximity Warning System). These provide warnings and spoken (verbal) resolution instructions through the ICAS (Indication and Crew Alerting System).

The auditory warnings produced by these systems usually include a warning attention sound followed by verbal command(s) to the pilot/crew. Probably most familiar to the average person is the "Pull up! Pull up!" command encountered in many video games and a few movies.

Other common spoken warnings are "Caution: terrain", "Windshear! Windshear!", or "Caution: traffic" followed by short directions on what actions the pilot should take to resolve the situation. The TCAS and TAWS/EGPWS are usually integrated to prevent conflicting advice, e.g. telling them to "Descend! Descend!" to avoid another aircraft when the aircraft is already close to the ground.

Modern Boeing and Airbus airliners both typically feature a male voice, which calls out height above terrain on approach to land, and other related warnings. Airbus aircraft usually feature a distinctive British accent (seen on recent builds of the A320 and all Airbus aircraft since the A330 and A340) or French accent (seen on ECAM-equipped A300s, A310s and early A320s).

A female voice was incorporated into McDonnell Douglas DC-9, MD-80/90, MD-11 and Boeing 717 (inherited from McDonnell Douglas after the merger with Boeing) series aircraft in the Central Aural Warning System (CAWS). This system provided a voice for most warnings, including fire, altitude, cabin altitude, stall, overspeed, autopilot disconnect and so on.

In more advanced cockpits on newer aircraft, there may be many other voice warnings managed by from ICAS such as "Gear up. Gear up." These may be warnings or simply declarative statements which augment the pilot's situation awareness.

Voice Gender

Early human factors research in aircraft and other domains indicated that female voices were more authoritative to male pilots and crew members and were more likely to get their attention. A lot of this research was based on pilot experiences, particularly in combat situations, where the pilots were being guided by female ground controllers. They reported being able to most easily pick out the female voice from amid the flurry of radio chatter.

More recent research, however, carried out since more females have begun working in aviation as pilots and ground controllers, indicates that the previous hypothesis may be unreliable. General human factors wisdom now indicates largely that, either due to current culture or changing attitudes, an automated female voice is no more or less effective than the male voice.

Edworthy et al (2003) at the University of Plymouth UK, for example, found that both acoustic and non-acoustic differences between male and female speakers were negligible. Therefore, they recommended, the choice of speaker should depend on the overlap of noise and speech spectra. Female voices did however appear to have an advantage in that they could portray a greater range of urgencies because of their usually higher pitch and pitch range. They reported an experiment showing that knowledge about the sex of a speaker has no effect on judgments of perceived urgency, with acoustic variables accounting for such differences .

Other applications

Voice warning systems included in automobiles of the late 1970s to early 1980s, such as the Datsun Z-Car Series found in the 280ZX, were also known as Bitching Betty. The Datsun system issued commands such as "lights are on," or "Left door is open." Datsun's original name for the feature was "Talking Lady."

Examples phrases

Sample Warnings from GPWS and EGPWS/TAWS

• "Terrain, Terrain"
• "WHOOP WHOOP! Pull Up!"
• "Too Low, Flaps"
• "Too Low, Gear"
• "Too Low, Terrain"
• "WHOOP WHOOP! Terrain!"
• "Windshear, Windshear, Windshear!"
• "Glideslope"
• "Sink rate"
• "Don't Sink!"
• "Bank Angle"

All Warnings from TCAS

• Climb, Climb
• Descend, Descend
• Climb, Crossing Climb -- Climb, Crossing Climb
• Descend, Crossing Descend -- Descend, Crossing Descend
• Adjust Vertical Speed, Adjust
• Climb, Climb NOW -- Climb, Climb NOW
• Descend, Descend NOW -- Descend, Descend NOW
• Increase Climb, Increase Climb
• Increase Descent, Increase Descent
• Maintain Vertical Speed, Maintain
• Maintain Vertical Speed, Crossing, Maintain
• Monitor Vertical Speed
• Clear of Conflict
• Traffic, Traffic
• Traffic
• TCAS System Test OK
• TCAS System Test Fail

Sample Warnings from CAWS found onboard DC-9/MD-80/MD-90/MD-11/B-717 aircraft

• "Config"
• "Stall, Stall"
• "Fire Left Engine"
• "Fire Right Engine"
• "APU Fire"
• "Altitude, Altitude"
• "Cabin Altitude"
• "Overspeed"
• "Autopilot"
• "Autobrake"
• "Autospoiler"
• "Landing Gear"
• "Flaps"
• "Slats"
• "Speedbrake"
• "Spoilers"
• "Stabilizer"
• "Stabilizer Motion"

References

• Stanton, N.A., and Edworthy, J., "Human Factors in Auditory Warnings", Ashgate, Aldershot, UK, 1999, ISBN 0 291 39849 9